dtc issue with overlays starting in next-20171009

dtc issue with overlays starting in next-20171009

[Alan Tull]

Hi Rob,

I've noticed a problem compiling DT overlays and traced it back to
beginning in next-20171009

That tag adds the following in scripts/dtc

e9480c1 2017-10-09 16:17:32 +0100 : Mark Brown : Merge remote-tracking
branch 'devicetree/for-next'
4201d05 2017-10-03 15:03:47 -0500 : Rob Herring : scripts/dtc: Update
to upstream version v1.4.5-3-gb1a60033c110
4322323 2017-10-03 15:03:46 -0500 : Rob Herring : scripts/dtc: add
fdt_overlay.c and fdt_addresses.c to sync script

The error is:

dtc: /home/atull/repos/linux-socfpga/scripts/dtc/livetree.c:543:
get_node_by_phandle: Assertion `(phandle != 0) && (phandle != -1)'
failed.
arch/arm/boot/dts/socfpga_overlay.dtb: Warning (clocks_property):
Could not get phandle node for
/fragment@0/__overlay__/gpio@10040:clocks(cell 0)
Aborted (core dumped)
scripts/Makefile.lib:316: recipe for target
'arch/arm/boot/dts/socfpga_arria10_socdk_sdmmc_ghrd_ovl_ext_cfg.dtb'
failed
make[2]: *** [arch/arm/boot/dts/socfpga_arria10_socdk_sdmmc_ghrd_ovl_ext_cfg.dtb]
Error 134
arch/arm/Makefile:346: recipe for target 'dtbs' failed

Here's a simplified overlay that gets this error.  Taking out the line
"interrupt-parent = <&intc>;" fixes the build.

/dts-v1/;
/plugin/;
/ {
        fragment@0 {
                target-path = "/soc/base_fpga_region";
                #address-cells = <1>;
                #size-cells = <1>;

                __overlay__ {
                        ranges = <0x00000000 0x00000000 0xc0000000 0x00040000>,
                                 <0x00000001 0x00000000 0xff200000 0x00001000>;

                        external-fpga-config;

                        #address-cells = <2>;
                        #size-cells = <1>;

                        fpga_pr_region0 {
                                compatible = "fpga-region";
                                fpga-bridges = <&freeze_controller_0>;
                                ranges;
                        };

                        freeze_controller_0: freeze_controller@0x100000450 {
                                compatible = "altr,freeze-bridge-controller";
                                reg = <0x00000001 0x00000450 0x00000010>;
                                interrupt-parent = <&intc>;  /* <--
remove to fix build */
                                interrupts = <0 21 4>;
                        };
                };
        };
};

Alan
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Re: dtc issue with overlays starting in next-20171009

[Frank Rowand]

Hi Rob, Alan,

On 10/18/17 08:58, Alan Tull wrote:
> Hi Rob,
> 
> I've noticed a problem compiling DT overlays and traced it back to
> beginning in next-20171009
> 
> That tag adds the following in scripts/dtc
> 
> e9480c1 2017-10-09 16:17:32 +0100 : Mark Brown : Merge remote-tracking
> branch 'devicetree/for-next'
> 4201d05 2017-10-03 15:03:47 -0500 : Rob Herring : scripts/dtc: Update
> to upstream version v1.4.5-3-gb1a60033c110
> 4322323 2017-10-03 15:03:46 -0500 : Rob Herring : scripts/dtc: add
> fdt_overlay.c and fdt_addresses.c to sync script
> 
> The error is:
> 
> dtc: /home/atull/repos/linux-socfpga/scripts/dtc/livetree.c:543:
> get_node_by_phandle: Assertion `(phandle != 0) && (phandle != -1)'
> failed.
> arch/arm/boot/dts/socfpga_overlay.dtb: Warning (clocks_property):
> Could not get phandle node for
> /fragment@0/__overlay__/gpio@10040:clocks(cell 0)
> Aborted (core dumped)
> scripts/Makefile.lib:316: recipe for target
> 'arch/arm/boot/dts/socfpga_arria10_socdk_sdmmc_ghrd_ovl_ext_cfg.dtb'
> failed
> make[2]: *** [arch/arm/boot/dts/socfpga_arria10_socdk_sdmmc_ghrd_ovl_ext_cfg.dtb]
> Error 134
> arch/arm/Makefile:346: recipe for target 'dtbs' failed
> 
> Here's a simplified overlay that gets this error.  Taking out the line
> "interrupt-parent = <&intc>;" fixes the build.
> 
> /dts-v1/;
> /plugin/;
> / {
>         fragment@0 {
>                 target-path = "/soc/base_fpga_region";
>                 #address-cells = <1>;
>                 #size-cells = <1>;
> 
>                 __overlay__ {
>                         ranges = <0x00000000 0x00000000 0xc0000000 0x00040000>,
>                                  <0x00000001 0x00000000 0xff200000 0x00001000>;
> 
>                         external-fpga-config;
> 
>                         #address-cells = <2>;
>                         #size-cells = <1>;
> 
>                         fpga_pr_region0 {
>                                 compatible = "fpga-region";
>                                 fpga-bridges = <&freeze_controller_0>;
>                                 ranges;
>                         };
> 
>                         freeze_controller_0: freeze_controller@0x100000450 {
>                                 compatible = "altr,freeze-bridge-controller";
>                                 reg = <0x00000001 0x00000450 0x00000010>;
>                                 interrupt-parent = <&intc>;  /* <--
> remove to fix build */
>                                 interrupts = <0 21 4>;
>                         };
>                 };
>         };
> };
> 
> Alan

Phandle references in overlays are assigned the value of -1 (0xffffffff) in
the dtb, to be fixed up when loaded.  A new check sees this value and
triggers the assert.

It is this commit in the upstream dtc tools tree:

   commit ee3d26f6960bb5922d9a35fe266d9eac74a78ec0
   checks: add interrupts property check

There are a bunch of other new checks that call get_node_by_phandle(),
and thus could trigger the assertion.

I'm guessing that those checks would also trigger the assert if an
overlay contained something that would lead to one of the other checks
being processed.

You can avoid the problem in your example dts with "-Wno-interrupts_property"

  dtc -Wno-interrupts_property fpga_01_a.dts

The larger set of other checks that might trigger the assert is too large
for me to want to add "-Wno-" flags for all of them to the command line
(as temporary workarounds).

-Frank

Re: dtc issue with overlays starting in next-20171009

[Rob Herring]

Use devicetree-compiler list for dtc issues please.

On Wed, Oct 18, 2017 at 2:33 PM, Frank Rowand <frowand.list-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:
> Hi Rob, Alan,
>
> On 10/18/17 08:58, Alan Tull wrote:
>> Hi Rob,
>>
>> I've noticed a problem compiling DT overlays and traced it back to
>> beginning in next-20171009
>>
>> That tag adds the following in scripts/dtc
>>
>> e9480c1 2017-10-09 16:17:32 +0100 : Mark Brown : Merge remote-tracking
>> branch 'devicetree/for-next'
>> 4201d05 2017-10-03 15:03:47 -0500 : Rob Herring : scripts/dtc: Update
>> to upstream version v1.4.5-3-gb1a60033c110
>> 4322323 2017-10-03 15:03:46 -0500 : Rob Herring : scripts/dtc: add
>> fdt_overlay.c and fdt_addresses.c to sync script
>>
>> The error is:
>>
>> dtc: /home/atull/repos/linux-socfpga/scripts/dtc/livetree.c:543:
>> get_node_by_phandle: Assertion `(phandle != 0) && (phandle != -1)'
>> failed.
>> arch/arm/boot/dts/socfpga_overlay.dtb: Warning (clocks_property):
>> Could not get phandle node for
>> /fragment@0/__overlay__/gpio@10040:clocks(cell 0)
>> Aborted (core dumped)
>> scripts/Makefile.lib:316: recipe for target
>> 'arch/arm/boot/dts/socfpga_arria10_socdk_sdmmc_ghrd_ovl_ext_cfg.dtb'
>> failed
>> make[2]: *** [arch/arm/boot/dts/socfpga_arria10_socdk_sdmmc_ghrd_ovl_ext_cfg.dtb]
>> Error 134
>> arch/arm/Makefile:346: recipe for target 'dtbs' failed
>>
>> Here's a simplified overlay that gets this error.  Taking out the line
>> "interrupt-parent = <&intc>;" fixes the build.
>>
>> /dts-v1/;
>> /plugin/;
>> / {
>>         fragment@0 {
>>                 target-path = "/soc/base_fpga_region";
>>                 #address-cells = <1>;
>>                 #size-cells = <1>;
>>
>>                 __overlay__ {
>>                         ranges = <0x00000000 0x00000000 0xc0000000 0x00040000>,
>>                                  <0x00000001 0x00000000 0xff200000 0x00001000>;
>>
>>                         external-fpga-config;
>>
>>                         #address-cells = <2>;
>>                         #size-cells = <1>;
>>
>>                         fpga_pr_region0 {
>>                                 compatible = "fpga-region";
>>                                 fpga-bridges = <&freeze_controller_0>;
>>                                 ranges;
>>                         };
>>
>>                         freeze_controller_0: freeze_controller@0x100000450 {
>>                                 compatible = "altr,freeze-bridge-controller";
>>                                 reg = <0x00000001 0x00000450 0x00000010>;
>>                                 interrupt-parent = <&intc>;  /* <--
>> remove to fix build */
>>                                 interrupts = <0 21 4>;
>>                         };
>>                 };
>>         };
>> };
>>
>> Alan
>
> Phandle references in overlays are assigned the value of -1 (0xffffffff) in
> the dtb, to be fixed up when loaded.  A new check sees this value and
> triggers the assert.
>
> It is this commit in the upstream dtc tools tree:
>
>    commit ee3d26f6960bb5922d9a35fe266d9eac74a78ec0
>    checks: add interrupts property check
>
> There are a bunch of other new checks that call get_node_by_phandle(),
> and thus could trigger the assertion.
>
> I'm guessing that those checks would also trigger the assert if an
> overlay contained something that would lead to one of the other checks
> being processed.

You won't get an assert because I check for 0 or -1 and skip the check
in those cases. The interrupts check missed that condition.

However, as shown above, you will get an erroneous warning because it
just skips 1 cell and goes to the next to handle the case where the
phandle is optional and you want a fixed number of elements.

I guess we can't validate overlays which is unfortunate. I don't think
that's a solvable problem unless you have the base DT.

> You can avoid the problem in your example dts with "-Wno-interrupts_property"
>
>   dtc -Wno-interrupts_property fpga_01_a.dts
>
> The larger set of other checks that might trigger the assert is too large
> for me to want to add "-Wno-" flags for all of them to the command line
> (as temporary workarounds).

David thought more switches were better.

Rob
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Re: dtc issue with overlays starting in next-20171009

[Frank Rowand]

On 10/18/17 13:16, Rob Herring wrote:
> Use devicetree-compiler list for dtc issues please.
> 
> On Wed, Oct 18, 2017 at 2:33 PM, Frank Rowand <frowand.list-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:
>> Hi Rob, Alan,
>>
>> On 10/18/17 08:58, Alan Tull wrote:
>>> Hi Rob,
>>>
>>> I've noticed a problem compiling DT overlays and traced it back to
>>> beginning in next-20171009
>>>
>>> That tag adds the following in scripts/dtc
>>>
>>> e9480c1 2017-10-09 16:17:32 +0100 : Mark Brown : Merge remote-tracking
>>> branch 'devicetree/for-next'
>>> 4201d05 2017-10-03 15:03:47 -0500 : Rob Herring : scripts/dtc: Update
>>> to upstream version v1.4.5-3-gb1a60033c110
>>> 4322323 2017-10-03 15:03:46 -0500 : Rob Herring : scripts/dtc: add
>>> fdt_overlay.c and fdt_addresses.c to sync script
>>>
>>> The error is:
>>>
>>> dtc: /home/atull/repos/linux-socfpga/scripts/dtc/livetree.c:543:
>>> get_node_by_phandle: Assertion `(phandle != 0) && (phandle != -1)'
>>> failed.
>>> arch/arm/boot/dts/socfpga_overlay.dtb: Warning (clocks_property):
>>> Could not get phandle node for
>>> /fragment@0/__overlay__/gpio@10040:clocks(cell 0)
>>> Aborted (core dumped)
>>> scripts/Makefile.lib:316: recipe for target
>>> 'arch/arm/boot/dts/socfpga_arria10_socdk_sdmmc_ghrd_ovl_ext_cfg.dtb'
>>> failed
>>> make[2]: *** [arch/arm/boot/dts/socfpga_arria10_socdk_sdmmc_ghrd_ovl_ext_cfg.dtb]
>>> Error 134
>>> arch/arm/Makefile:346: recipe for target 'dtbs' failed
>>>
>>> Here's a simplified overlay that gets this error.  Taking out the line
>>> "interrupt-parent = <&intc>;" fixes the build.
>>>
>>> /dts-v1/;
>>> /plugin/;
>>> / {
>>>         fragment@0 {
>>>                 target-path = "/soc/base_fpga_region";
>>>                 #address-cells = <1>;
>>>                 #size-cells = <1>;
>>>
>>>                 __overlay__ {
>>>                         ranges = <0x00000000 0x00000000 0xc0000000 0x00040000>,
>>>                                  <0x00000001 0x00000000 0xff200000 0x00001000>;
>>>
>>>                         external-fpga-config;
>>>
>>>                         #address-cells = <2>;
>>>                         #size-cells = <1>;
>>>
>>>                         fpga_pr_region0 {
>>>                                 compatible = "fpga-region";
>>>                                 fpga-bridges = <&freeze_controller_0>;
>>>                                 ranges;
>>>                         };
>>>
>>>                         freeze_controller_0: freeze_controller@0x100000450 {
>>>                                 compatible = "altr,freeze-bridge-controller";
>>>                                 reg = <0x00000001 0x00000450 0x00000010>;
>>>                                 interrupt-parent = <&intc>;  /* <--
>>> remove to fix build */
>>>                                 interrupts = <0 21 4>;
>>>                         };
>>>                 };
>>>         };
>>> };
>>>
>>> Alan
>>
>> Phandle references in overlays are assigned the value of -1 (0xffffffff) in
>> the dtb, to be fixed up when loaded.  A new check sees this value and
>> triggers the assert.
>>
>> It is this commit in the upstream dtc tools tree:
>>
>>    commit ee3d26f6960bb5922d9a35fe266d9eac74a78ec0
>>    checks: add interrupts property check
>>
>> There are a bunch of other new checks that call get_node_by_phandle(),
>> and thus could trigger the assertion.
>>
>> I'm guessing that those checks would also trigger the assert if an
>> overlay contained something that would lead to one of the other checks
>> being processed.
> 
> You won't get an assert because I check for 0 or -1 and skip the check
> in those cases. The interrupts check missed that condition.

Awesome, thank for confirming that.  That means the temporary work around
is quite easy.

> 
> However, as shown above, you will get an erroneous warning because it
> just skips 1 cell and goes to the next to handle the case where the
> phandle is optional and you want a fixed number of elements.

Just for those reading along at home, with the one warning disabled, the
messages become:

   $  dtc -Wno-interrupts_property socfpga_arria10_socdk_sdmmc_ghrd_ovl_ext_cfg.dts >junk.dtb
   <stdout>: Warning (unit_address_vs_reg): Node /fragment@0 has a unit name, but no reg property
   <stdout>: Warning (unit_address_vs_reg): Node /fragment@0/__overlay__ has a reg or ranges property, but no unit name


> I guess we can't validate overlays which is unfortunate. I don't think
> that's a solvable problem unless you have the base DT.

Yes, maybe.  But there are still some useful warnings for overlays, maybe.  I'm
not sure what the implications of the "range_format" warning that I will show
below are (I'd actually have to spend a few minutes thinking about ranges, and
I don't have the cycles right now).


> 
>> You can avoid the problem in your example dts with "-Wno-interrupts_property"
>>
>>   dtc -Wno-interrupts_property fpga_01_a.dts
>>
>> The larger set of other checks that might trigger the assert is too large
>> for me to want to add "-Wno-" flags for all of them to the command line
>> (as temporary workarounds).
> 
> David thought more switches were better.

Yep.  Not a complaint, just an observation about a _temporary_ workaround.


> 
> Rob
> 


Here is the "range_format" warning I mentioned above.  The dts file that
started this thread hand crafts what is internal overlay data, which
should be generated by the dtc compiler instead of being hand coded in
the dts.  If I remove the hand coded stuff and let dtc generate the
internal overlay data, the dtc messages become (use a wide window to
avoid line wrapping):

$ dtc -Wno-interrupts_property fpga_01_a.dts >junk.dtb
<stdout>: Warning (ranges_format): "ranges" property in /fragment@0/__overlay__ has invalid length (32 bytes) (parent #address-cells == 2, child #address-cells == 2, #size-cells == 1)
<stdout>: Warning (unit_address_vs_reg): Node /fragment@0 has a unit name, but no reg property
<stdout>: Warning (unit_address_vs_reg): Node /fragment@0/__overlay__ has a reg or ranges property, but no unit name
<stdout>: Warning (avoid_default_addr_size): Relying on default #address-cells value for /fragment@0/__overlay__
<stdout>: Warning (avoid_default_addr_size): Relying on default #size-cells value for /fragment@0/__overlay__


The second through last warning are about the format of the internal
data structure, and hopefully could just be suppressed.  I don't
know how easy or hard that would be to implement - I am very much
not a dtc internals expert.

The first warning says something about what the overlay source dts
contains.  Here is what the original dts source looks like when
transformed to not contain the hand crafted internal overlay data:

$ cat fpga_01_a.dts 
/dts-v1/;
/plugin/;

// This assumes an existing label in the base dts
// whose location is "/soc/base_fpga_region"
&fpga_region {

			ranges = <0x00000000 0x00000000 0xc0000000 0x00040000>,
				 <0x00000001 0x00000000 0xff200000 0x00001000>;

			external-fpga-config;

			#address-cells = <2>;
			#size-cells = <1>;

			fpga_pr_region0 {
				compatible = "fpga-region";
				fpga-bridges = <&freeze_controller_0>;
				ranges;
			};

			freeze_controller_0: freeze_controller@100000450 {
				compatible = "altr,freeze-bridge-controller";
				reg = <0x00000001 0x00000450 0x00000010>;
				interrupt-parent = <&intc>;  /* <-- remove to fix build */
				interrupts = <0 21 4>;
			};
};

Of course, if this was a real transformation, I would remove all the
extra tabbing.  But the current form makes it easier to see that all
of the stuff that is highly indented is unchanged from the original
dts file.

$ diff -u socfpga_arria10_socdk_sdmmc_ghrd_ovl_ext_cfg.dts fpga_01_a.dts
--- socfpga_arria10_socdk_sdmmc_ghrd_ovl_ext_cfg.dts	2017-10-18 15:18:43.123137508 -0700
+++ fpga_01_a.dts	2017-10-18 15:18:11.587136897 -0700
@@ -1,12 +1,10 @@
 /dts-v1/;
 /plugin/;
-/ {
-	fragment@0 {
-		target-path = "/soc/base_fpga_region";
-		#address-cells = <1>;
-		#size-cells = <1>;
 
-		__overlay__ {
+// This assumes an existing label in the base dts
+// whose location is "/soc/base_fpga_region"
+&fpga_region {
+
 			ranges = <0x00000000 0x00000000 0xc0000000 0x00040000>,
 				 <0x00000001 0x00000000 0xff200000 0x00001000>;
 
@@ -27,6 +25,4 @@
 				interrupt-parent = <&intc>;  /* <-- remove to fix build */
 				interrupts = <0 21 4>;
 			};
-		};
-	};
 };


-Frank

Re: dtc issue with overlays starting in next-20171009

[Rob Herring]

On Wed, Oct 18, 2017 at 5:34 PM, Frank Rowand <frowand.list-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:
> On 10/18/17 13:16, Rob Herring wrote:
>> Use devicetree-compiler list for dtc issues please.
>>
>> On Wed, Oct 18, 2017 at 2:33 PM, Frank Rowand <frowand.list-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:
>>> Hi Rob, Alan,
>>>
>>> On 10/18/17 08:58, Alan Tull wrote:
>>>> Hi Rob,
>>>>
>>>> I've noticed a problem compiling DT overlays and traced it back to
>>>> beginning in next-20171009
>>>>
>>>> That tag adds the following in scripts/dtc
>>>>
>>>> e9480c1 2017-10-09 16:17:32 +0100 : Mark Brown : Merge remote-tracking
>>>> branch 'devicetree/for-next'
>>>> 4201d05 2017-10-03 15:03:47 -0500 : Rob Herring : scripts/dtc: Update
>>>> to upstream version v1.4.5-3-gb1a60033c110
>>>> 4322323 2017-10-03 15:03:46 -0500 : Rob Herring : scripts/dtc: add
>>>> fdt_overlay.c and fdt_addresses.c to sync script
>>>>
>>>> The error is:
>>>>
>>>> dtc: /home/atull/repos/linux-socfpga/scripts/dtc/livetree.c:543:
>>>> get_node_by_phandle: Assertion `(phandle != 0) && (phandle != -1)'
>>>> failed.
>>>> arch/arm/boot/dts/socfpga_overlay.dtb: Warning (clocks_property):
>>>> Could not get phandle node for
>>>> /fragment@0/__overlay__/gpio@10040:clocks(cell 0)
>>>> Aborted (core dumped)
>>>> scripts/Makefile.lib:316: recipe for target
>>>> 'arch/arm/boot/dts/socfpga_arria10_socdk_sdmmc_ghrd_ovl_ext_cfg.dtb'
>>>> failed
>>>> make[2]: *** [arch/arm/boot/dts/socfpga_arria10_socdk_sdmmc_ghrd_ovl_ext_cfg.dtb]
>>>> Error 134
>>>> arch/arm/Makefile:346: recipe for target 'dtbs' failed
>>>>
>>>> Here's a simplified overlay that gets this error.  Taking out the line
>>>> "interrupt-parent = <&intc>;" fixes the build.
>>>>
>>>> /dts-v1/;
>>>> /plugin/;
>>>> / {
>>>>         fragment@0 {
>>>>                 target-path = "/soc/base_fpga_region";
>>>>                 #address-cells = <1>;
>>>>                 #size-cells = <1>;
>>>>
>>>>                 __overlay__ {
>>>>                         ranges = <0x00000000 0x00000000 0xc0000000 0x00040000>,
>>>>                                  <0x00000001 0x00000000 0xff200000 0x00001000>;
>>>>
>>>>                         external-fpga-config;
>>>>
>>>>                         #address-cells = <2>;
>>>>                         #size-cells = <1>;
>>>>
>>>>                         fpga_pr_region0 {
>>>>                                 compatible = "fpga-region";
>>>>                                 fpga-bridges = <&freeze_controller_0>;
>>>>                                 ranges;
>>>>                         };
>>>>
>>>>                         freeze_controller_0: freeze_controller@0x100000450 {
>>>>                                 compatible = "altr,freeze-bridge-controller";
>>>>                                 reg = <0x00000001 0x00000450 0x00000010>;
>>>>                                 interrupt-parent = <&intc>;  /* <--
>>>> remove to fix build */
>>>>                                 interrupts = <0 21 4>;
>>>>                         };
>>>>                 };
>>>>         };
>>>> };
>>>>
>>>> Alan
>>>
>>> Phandle references in overlays are assigned the value of -1 (0xffffffff) in
>>> the dtb, to be fixed up when loaded.  A new check sees this value and
>>> triggers the assert.
>>>
>>> It is this commit in the upstream dtc tools tree:
>>>
>>>    commit ee3d26f6960bb5922d9a35fe266d9eac74a78ec0
>>>    checks: add interrupts property check
>>>
>>> There are a bunch of other new checks that call get_node_by_phandle(),
>>> and thus could trigger the assertion.
>>>
>>> I'm guessing that those checks would also trigger the assert if an
>>> overlay contained something that would lead to one of the other checks
>>> being processed.
>>
>> You won't get an assert because I check for 0 or -1 and skip the check
>> in those cases. The interrupts check missed that condition.
>
> Awesome, thank for confirming that.  That means the temporary work around
> is quite easy.
>
>>
>> However, as shown above, you will get an erroneous warning because it
>> just skips 1 cell and goes to the next to handle the case where the
>> phandle is optional and you want a fixed number of elements.
>
> Just for those reading along at home, with the one warning disabled, the
> messages become:
>
>    $  dtc -Wno-interrupts_property socfpga_arria10_socdk_sdmmc_ghrd_ovl_ext_cfg.dts >junk.dtb
>    <stdout>: Warning (unit_address_vs_reg): Node /fragment@0 has a unit name, but no reg property
>    <stdout>: Warning (unit_address_vs_reg): Node /fragment@0/__overlay__ has a reg or ranges property, but no unit name

Look like errors to me.

>> I guess we can't validate overlays which is unfortunate. I don't think
>> that's a solvable problem unless you have the base DT.
>
> Yes, maybe.  But there are still some useful warnings for overlays, maybe.  I'm
> not sure what the implications of the "range_format" warning that I will show
> below are (I'd actually have to spend a few minutes thinking about ranges, and
> I don't have the cycles right now).

Well, yes all the simple localized checks should work, but as we add
more complex checks with either dtc or the schema we'll have after
ELCE next week there's a lot we can't validate. Perhaps we have to
place some restrictions on overlays so we can validate them better.

I do wonder if we could add tags to phandles to make them
identifiable. Perhaps making them all 0xFF?????? instead of starting
at 1. 2^24 phandles should be enough for anyone(TM). That would not
completely solve this problem, but then we could at least find the
phandles in a property.

Rob

Re: dtc issue with overlays starting in next-20171009

[David Gibson]

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On Wed, Oct 18, 2017 at 07:17:04PM -0500, Rob Herring wrote:
> On Wed, Oct 18, 2017 at 5:34 PM, Frank Rowand <frowand.list@gmail.com> wrote:
> > On 10/18/17 13:16, Rob Herring wrote:
> >> Use devicetree-compiler list for dtc issues please.
> >>
> >> On Wed, Oct 18, 2017 at 2:33 PM, Frank Rowand <frowand.list@gmail.com> wrote:
> >>> Hi Rob, Alan,
> >>>
> >>> On 10/18/17 08:58, Alan Tull wrote:
> >>>> Hi Rob,
> >>>>
> >>>> I've noticed a problem compiling DT overlays and traced it back to
> >>>> beginning in next-20171009
> >>>>
> >>>> That tag adds the following in scripts/dtc
> >>>>
> >>>> e9480c1 2017-10-09 16:17:32 +0100 : Mark Brown : Merge remote-tracking
> >>>> branch 'devicetree/for-next'
> >>>> 4201d05 2017-10-03 15:03:47 -0500 : Rob Herring : scripts/dtc: Update
> >>>> to upstream version v1.4.5-3-gb1a60033c110
> >>>> 4322323 2017-10-03 15:03:46 -0500 : Rob Herring : scripts/dtc: add
> >>>> fdt_overlay.c and fdt_addresses.c to sync script
> >>>>
> >>>> The error is:
> >>>>
> >>>> dtc: /home/atull/repos/linux-socfpga/scripts/dtc/livetree.c:543:
> >>>> get_node_by_phandle: Assertion `(phandle != 0) && (phandle != -1)'
> >>>> failed.
> >>>> arch/arm/boot/dts/socfpga_overlay.dtb: Warning (clocks_property):
> >>>> Could not get phandle node for
> >>>> /fragment@0/__overlay__/gpio@10040:clocks(cell 0)
> >>>> Aborted (core dumped)
> >>>> scripts/Makefile.lib:316: recipe for target
> >>>> 'arch/arm/boot/dts/socfpga_arria10_socdk_sdmmc_ghrd_ovl_ext_cfg.dtb'
> >>>> failed
> >>>> make[2]: *** [arch/arm/boot/dts/socfpga_arria10_socdk_sdmmc_ghrd_ovl_ext_cfg.dtb]
> >>>> Error 134
> >>>> arch/arm/Makefile:346: recipe for target 'dtbs' failed
> >>>>
> >>>> Here's a simplified overlay that gets this error.  Taking out the line
> >>>> "interrupt-parent = <&intc>;" fixes the build.
> >>>>
> >>>> /dts-v1/;
> >>>> /plugin/;
> >>>> / {
> >>>>         fragment@0 {
> >>>>                 target-path = "/soc/base_fpga_region";
> >>>>                 #address-cells = <1>;
> >>>>                 #size-cells = <1>;
> >>>>
> >>>>                 __overlay__ {
> >>>>                         ranges = <0x00000000 0x00000000 0xc0000000 0x00040000>,
> >>>>                                  <0x00000001 0x00000000 0xff200000 0x00001000>;
> >>>>
> >>>>                         external-fpga-config;
> >>>>
> >>>>                         #address-cells = <2>;
> >>>>                         #size-cells = <1>;
> >>>>
> >>>>                         fpga_pr_region0 {
> >>>>                                 compatible = "fpga-region";
> >>>>                                 fpga-bridges = <&freeze_controller_0>;
> >>>>                                 ranges;
> >>>>                         };
> >>>>
> >>>>                         freeze_controller_0: freeze_controller@0x100000450 {
> >>>>                                 compatible = "altr,freeze-bridge-controller";
> >>>>                                 reg = <0x00000001 0x00000450 0x00000010>;
> >>>>                                 interrupt-parent = <&intc>;  /* <--
> >>>> remove to fix build */
> >>>>                                 interrupts = <0 21 4>;
> >>>>                         };
> >>>>                 };
> >>>>         };
> >>>> };
> >>>>
> >>>> Alan
> >>>
> >>> Phandle references in overlays are assigned the value of -1 (0xffffffff) in
> >>> the dtb, to be fixed up when loaded.  A new check sees this value and
> >>> triggers the assert.
> >>>
> >>> It is this commit in the upstream dtc tools tree:
> >>>
> >>>    commit ee3d26f6960bb5922d9a35fe266d9eac74a78ec0
> >>>    checks: add interrupts property check
> >>>
> >>> There are a bunch of other new checks that call get_node_by_phandle(),
> >>> and thus could trigger the assertion.
> >>>
> >>> I'm guessing that those checks would also trigger the assert if an
> >>> overlay contained something that would lead to one of the other checks
> >>> being processed.
> >>
> >> You won't get an assert because I check for 0 or -1 and skip the check
> >> in those cases. The interrupts check missed that condition.
> >
> > Awesome, thank for confirming that.  That means the temporary work around
> > is quite easy.
> >
> >>
> >> However, as shown above, you will get an erroneous warning because it
> >> just skips 1 cell and goes to the next to handle the case where the
> >> phandle is optional and you want a fixed number of elements.
> >
> > Just for those reading along at home, with the one warning disabled, the
> > messages become:
> >
> >    $  dtc -Wno-interrupts_property socfpga_arria10_socdk_sdmmc_ghrd_ovl_ext_cfg.dts >junk.dtb
> >    <stdout>: Warning (unit_address_vs_reg): Node /fragment@0 has a unit name, but no reg property
> >    <stdout>: Warning (unit_address_vs_reg): Node /fragment@0/__overlay__ has a reg or ranges property, but no unit name
> 
> Look like errors to me.
> 
> >> I guess we can't validate overlays which is unfortunate. I don't think
> >> that's a solvable problem unless you have the base DT.
> >
> > Yes, maybe.  But there are still some useful warnings for overlays, maybe.  I'm
> > not sure what the implications of the "range_format" warning that I will show
> > below are (I'd actually have to spend a few minutes thinking about ranges, and
> > I don't have the cycles right now).
> 
> Well, yes all the simple localized checks should work, but as we add
> more complex checks with either dtc or the schema we'll have after
> ELCE next week there's a lot we can't validate. Perhaps we have to
> place some restrictions on overlays so we can validate them better.

Reworking overlay handling in dtc will help at least insofar as making
it easier to work out which checks can be applied to overlay fragments
and which only make sense on a fully assembled tree.  There will still
be plenty of things that can't be checked on overlays, since they
absolitely require information from the base tree.

This is a reason I really prefer the (alas, stalled) connector
proposal, since it makes it much more explicit what the external
dependencies of the fragments are.

> I do wonder if we could add tags to phandles to make them
> identifiable. Perhaps making them all 0xFF?????? instead of starting
> at 1. 2^24 phandles should be enough for anyone(TM).

True, in a sense.  However this is a problem for systems generating
FDTs from a real OF.  On real OF, the phandles are usually pointers
inside OF, and if it happens to allocate it's memory at the top of the
address space, phandles in the 0xff?????? range are entirely
plausible.

0 and -1 are the only values explicitly disallowed by IEEE1275, so
they're the only safe values to use as markers.

> That would not
> completely solve this problem, but then we could at least find the
> phandles in a property.

No, it wouldn't do that reliably, because a 0xff?????? value could
just as well appear as another integer value in a property.

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson

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Re: dtc issue with overlays starting in next-20171009

[David Gibson]

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On Wed, Oct 18, 2017 at 03:34:08PM -0700, Frank Rowand wrote:
> On 10/18/17 13:16, Rob Herring wrote:
> > Use devicetree-compiler list for dtc issues please.
> > 
> > On Wed, Oct 18, 2017 at 2:33 PM, Frank Rowand <frowand.list-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:
> >> Hi Rob, Alan,
> >>
> >> On 10/18/17 08:58, Alan Tull wrote:
> >>> Hi Rob,
> >>>
> >>> I've noticed a problem compiling DT overlays and traced it back to
> >>> beginning in next-20171009
> >>>
> >>> That tag adds the following in scripts/dtc
> >>>
> >>> e9480c1 2017-10-09 16:17:32 +0100 : Mark Brown : Merge remote-tracking
> >>> branch 'devicetree/for-next'
> >>> 4201d05 2017-10-03 15:03:47 -0500 : Rob Herring : scripts/dtc: Update
> >>> to upstream version v1.4.5-3-gb1a60033c110
> >>> 4322323 2017-10-03 15:03:46 -0500 : Rob Herring : scripts/dtc: add
> >>> fdt_overlay.c and fdt_addresses.c to sync script
> >>>
> >>> The error is:
> >>>
> >>> dtc: /home/atull/repos/linux-socfpga/scripts/dtc/livetree.c:543:
> >>> get_node_by_phandle: Assertion `(phandle != 0) && (phandle != -1)'
> >>> failed.
> >>> arch/arm/boot/dts/socfpga_overlay.dtb: Warning (clocks_property):
> >>> Could not get phandle node for
> >>> /fragment@0/__overlay__/gpio@10040:clocks(cell 0)
> >>> Aborted (core dumped)
> >>> scripts/Makefile.lib:316: recipe for target
> >>> 'arch/arm/boot/dts/socfpga_arria10_socdk_sdmmc_ghrd_ovl_ext_cfg.dtb'
> >>> failed
> >>> make[2]: *** [arch/arm/boot/dts/socfpga_arria10_socdk_sdmmc_ghrd_ovl_ext_cfg.dtb]
> >>> Error 134
> >>> arch/arm/Makefile:346: recipe for target 'dtbs' failed
> >>>
> >>> Here's a simplified overlay that gets this error.  Taking out the line
> >>> "interrupt-parent = <&intc>;" fixes the build.
> >>>
> >>> /dts-v1/;
> >>> /plugin/;
> >>> / {
> >>>         fragment@0 {
> >>>                 target-path = "/soc/base_fpga_region";
> >>>                 #address-cells = <1>;
> >>>                 #size-cells = <1>;
> >>>
> >>>                 __overlay__ {
> >>>                         ranges = <0x00000000 0x00000000 0xc0000000 0x00040000>,
> >>>                                  <0x00000001 0x00000000 0xff200000 0x00001000>;
> >>>
> >>>                         external-fpga-config;
> >>>
> >>>                         #address-cells = <2>;
> >>>                         #size-cells = <1>;
> >>>
> >>>                         fpga_pr_region0 {
> >>>                                 compatible = "fpga-region";
> >>>                                 fpga-bridges = <&freeze_controller_0>;
> >>>                                 ranges;
> >>>                         };
> >>>
> >>>                         freeze_controller_0: freeze_controller@0x100000450 {
> >>>                                 compatible = "altr,freeze-bridge-controller";
> >>>                                 reg = <0x00000001 0x00000450 0x00000010>;
> >>>                                 interrupt-parent = <&intc>;  /* <--
> >>> remove to fix build */
> >>>                                 interrupts = <0 21 4>;
> >>>                         };
> >>>                 };
> >>>         };
> >>> };
> >>>
> >>> Alan
> >>
> >> Phandle references in overlays are assigned the value of -1 (0xffffffff) in
> >> the dtb, to be fixed up when loaded.  A new check sees this value and
> >> triggers the assert.
> >>
> >> It is this commit in the upstream dtc tools tree:
> >>
> >>    commit ee3d26f6960bb5922d9a35fe266d9eac74a78ec0
> >>    checks: add interrupts property check
> >>
> >> There are a bunch of other new checks that call get_node_by_phandle(),
> >> and thus could trigger the assertion.
> >>
> >> I'm guessing that those checks would also trigger the assert if an
> >> overlay contained something that would lead to one of the other checks
> >> being processed.
> > 
> > You won't get an assert because I check for 0 or -1 and skip the check
> > in those cases. The interrupts check missed that condition.
> 
> Awesome, thank for confirming that.  That means the temporary work around
> is quite easy.
> 
> > 
> > However, as shown above, you will get an erroneous warning because it
> > just skips 1 cell and goes to the next to handle the case where the
> > phandle is optional and you want a fixed number of elements.
> 
> Just for those reading along at home, with the one warning disabled, the
> messages become:
> 
>    $  dtc -Wno-interrupts_property socfpga_arria10_socdk_sdmmc_ghrd_ovl_ext_cfg.dts >junk.dtb
>    <stdout>: Warning (unit_address_vs_reg): Node /fragment@0 has a unit name, but no reg property
>    <stdout>: Warning (unit_address_vs_reg): Node /fragment@0/__overlay__ has a reg or ranges property, but no unit name

Ah.. yeah.. we should put in explicit handling of this.  The top level
nodes in an overlay don't really obey the normal DT rules, so we
shouldn't apply the checks to them in the same way.

This, incidentally was a major part of why I want to change overlay
construction so it's done as a separate pass, rather than during the
parse: that way we can apply the checks separately to each fragment
before we assemble them, which I think will work better in most
cases.  (well, actually, the plan was to have two groups of checks -
some that run before overlay assembly, some after).  I made a start on
this in the 'overlay' branch, but I never got a chance to finish it.

> > I guess we can't validate overlays which is unfortunate. I don't think
> > that's a solvable problem unless you have the base DT.
> 
> Yes, maybe.  But there are still some useful warnings for overlays, maybe.  I'm
> not sure what the implications of the "range_format" warning that I will show
> below are (I'd actually have to spend a few minutes thinking about ranges, and
> I don't have the cycles right now).
> 
> 
> > 
> >> You can avoid the problem in your example dts with "-Wno-interrupts_property"
> >>
> >>   dtc -Wno-interrupts_property fpga_01_a.dts
> >>
> >> The larger set of other checks that might trigger the assert is too large
> >> for me to want to add "-Wno-" flags for all of them to the command line
> >> (as temporary workarounds).
> > 
> > David thought more switches were better.
> 
> Yep.  Not a complaint, just an observation about a _temporary_ workaround.
> 
> 
> > 
> > Rob
> > 
> 
> 
> Here is the "range_format" warning I mentioned above.  The dts file that
> started this thread hand crafts what is internal overlay data, which
> should be generated by the dtc compiler instead of being hand coded in
> the dts.  If I remove the hand coded stuff and let dtc generate the
> internal overlay data, the dtc messages become (use a wide window to
> avoid line wrapping):
> 
> $ dtc -Wno-interrupts_property fpga_01_a.dts >junk.dtb
> <stdout>: Warning (ranges_format): "ranges" property in /fragment@0/__overlay__ has invalid length (32 bytes) (parent #address-cells == 2, child #address-cells == 2, #size-cells == 1)

This is a false positive.  Correctly parsing the ranges property
requires knowing the parent node's #address-cells and #size-cells.  In
the case of an overlay, we don't know the real parent until it's
applied, so we can't check this.

So this probably needs another change to skip this test on the top
node of any overlay fragment.  Again, this would be easier if overlay
juggling was in a separate pass.

> <stdout>: Warning (unit_address_vs_reg): Node /fragment@0 has a unit name, but no reg property
> <stdout>: Warning (unit_address_vs_reg): Node /fragment@0/__overlay__ has a reg or ranges property, but no unit name
> <stdout>: Warning (avoid_default_addr_size): Relying on default #address-cells value for /fragment@0/__overlay__
> <stdout>: Warning (avoid_default_addr_size): Relying on default #size-cells value for /fragment@0/__overlay__
> 
> 
> The second through last warning are about the format of the internal
> data structure, and hopefully could just be suppressed.  I don't
> know how easy or hard that would be to implement - I am very much
> not a dtc internals expert.

Right, we shouldn't be applying these checks to nodes that are part of
the overlay metadata rather than "real" nodes.

> The first warning says something about what the overlay source dts
> contains.  Here is what the original dts source looks like when
> transformed to not contain the hand crafted internal overlay data:
> 
> $ cat fpga_01_a.dts 
> /dts-v1/;
> /plugin/;
> 
> // This assumes an existing label in the base dts
> // whose location is "/soc/base_fpga_region"
> &fpga_region {
> 
> 			ranges = <0x00000000 0x00000000 0xc0000000 0x00040000>,
> 				 <0x00000001 0x00000000 0xff200000 0x00001000>;
> 
> 			external-fpga-config;
> 
> 			#address-cells = <2>;
> 			#size-cells = <1>;
> 
> 			fpga_pr_region0 {
> 				compatible = "fpga-region";
> 				fpga-bridges = <&freeze_controller_0>;
> 				ranges;
> 			};
> 
> 			freeze_controller_0: freeze_controller@100000450 {
> 				compatible = "altr,freeze-bridge-controller";
> 				reg = <0x00000001 0x00000450 0x00000010>;
> 				interrupt-parent = <&intc>;  /* <-- remove to fix build */
> 				interrupts = <0 21 4>;
> 			};
> };
> 
> Of course, if this was a real transformation, I would remove all the
> extra tabbing.  But the current form makes it easier to see that all
> of the stuff that is highly indented is unchanged from the original
> dts file.
> 
> $ diff -u socfpga_arria10_socdk_sdmmc_ghrd_ovl_ext_cfg.dts fpga_01_a.dts
> --- socfpga_arria10_socdk_sdmmc_ghrd_ovl_ext_cfg.dts	2017-10-18 15:18:43.123137508 -0700
> +++ fpga_01_a.dts	2017-10-18 15:18:11.587136897 -0700
> @@ -1,12 +1,10 @@
>  /dts-v1/;
>  /plugin/;
> -/ {
> -	fragment@0 {
> -		target-path = "/soc/base_fpga_region";
> -		#address-cells = <1>;
> -		#size-cells = <1>;
>  
> -		__overlay__ {
> +// This assumes an existing label in the base dts
> +// whose location is "/soc/base_fpga_region"
> +&fpga_region {
> +
>  			ranges = <0x00000000 0x00000000 0xc0000000 0x00040000>,
>  				 <0x00000001 0x00000000 0xff200000 0x00001000>;
>  
> @@ -27,6 +25,4 @@
>  				interrupt-parent = <&intc>;  /* <-- remove to fix build */
>  				interrupts = <0 21 4>;
>  			};
> -		};
> -	};
>  };
> 
> 
> -Frank

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson

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Re: dtc issue with overlays starting in next-20171009

[Alan Tull]

On Wed, Oct 18, 2017 at 5:34 PM, Frank Rowand <frowand.list@gmail.com> wrote:
> On 10/18/17 13:16, Rob Herring wrote:
>> Use devicetree-compiler list for dtc issues please.
>>
>> On Wed, Oct 18, 2017 at 2:33 PM, Frank Rowand <frowand.list@gmail.com> wrote:
>>> Hi Rob, Alan,
>>>
>>> On 10/18/17 08:58, Alan Tull wrote:
>>>> Hi Rob,
>>>>
>>>> I've noticed a problem compiling DT overlays and traced it back to
>>>> beginning in next-20171009
>>>>
>>>> That tag adds the following in scripts/dtc
>>>>
>>>> e9480c1 2017-10-09 16:17:32 +0100 : Mark Brown : Merge remote-tracking
>>>> branch 'devicetree/for-next'
>>>> 4201d05 2017-10-03 15:03:47 -0500 : Rob Herring : scripts/dtc: Update
>>>> to upstream version v1.4.5-3-gb1a60033c110
>>>> 4322323 2017-10-03 15:03:46 -0500 : Rob Herring : scripts/dtc: add
>>>> fdt_overlay.c and fdt_addresses.c to sync script
>>>>
>>>> The error is:
>>>>
>>>> dtc: /home/atull/repos/linux-socfpga/scripts/dtc/livetree.c:543:
>>>> get_node_by_phandle: Assertion `(phandle != 0) && (phandle != -1)'
>>>> failed.
>>>> arch/arm/boot/dts/socfpga_overlay.dtb: Warning (clocks_property):
>>>> Could not get phandle node for
>>>> /fragment@0/__overlay__/gpio@10040:clocks(cell 0)
>>>> Aborted (core dumped)
>>>> scripts/Makefile.lib:316: recipe for target
>>>> 'arch/arm/boot/dts/socfpga_arria10_socdk_sdmmc_ghrd_ovl_ext_cfg.dtb'
>>>> failed
>>>> make[2]: *** [arch/arm/boot/dts/socfpga_arria10_socdk_sdmmc_ghrd_ovl_ext_cfg.dtb]
>>>> Error 134
>>>> arch/arm/Makefile:346: recipe for target 'dtbs' failed
>>>>
>>>> Here's a simplified overlay that gets this error.  Taking out the line
>>>> "interrupt-parent = <&intc>;" fixes the build.
>>>>
>>>> /dts-v1/;
>>>> /plugin/;
>>>> / {
>>>>         fragment@0 {
>>>>                 target-path = "/soc/base_fpga_region";
>>>>                 #address-cells = <1>;
>>>>                 #size-cells = <1>;
>>>>
>>>>                 __overlay__ {
>>>>                         ranges = <0x00000000 0x00000000 0xc0000000 0x00040000>,
>>>>                                  <0x00000001 0x00000000 0xff200000 0x00001000>;
>>>>
>>>>                         external-fpga-config;
>>>>
>>>>                         #address-cells = <2>;
>>>>                         #size-cells = <1>;
>>>>
>>>>                         fpga_pr_region0 {
>>>>                                 compatible = "fpga-region";
>>>>                                 fpga-bridges = <&freeze_controller_0>;
>>>>                                 ranges;
>>>>                         };
>>>>
>>>>                         freeze_controller_0: freeze_controller@0x100000450 {
>>>>                                 compatible = "altr,freeze-bridge-controller";
>>>>                                 reg = <0x00000001 0x00000450 0x00000010>;
>>>>                                 interrupt-parent = <&intc>;  /* <--
>>>> remove to fix build */
>>>>                                 interrupts = <0 21 4>;
>>>>                         };
>>>>                 };
>>>>         };
>>>> };
>>>>
>>>> Alan
>>>
>>> Phandle references in overlays are assigned the value of -1 (0xffffffff) in
>>> the dtb, to be fixed up when loaded.  A new check sees this value and
>>> triggers the assert.
>>>
>>> It is this commit in the upstream dtc tools tree:
>>>
>>>    commit ee3d26f6960bb5922d9a35fe266d9eac74a78ec0
>>>    checks: add interrupts property check
>>>
>>> There are a bunch of other new checks that call get_node_by_phandle(),
>>> and thus could trigger the assertion.
>>>
>>> I'm guessing that those checks would also trigger the assert if an
>>> overlay contained something that would lead to one of the other checks
>>> being processed.
>>
>> You won't get an assert because I check for 0 or -1 and skip the check
>> in those cases. The interrupts check missed that condition.
>
> Awesome, thank for confirming that.  That means the temporary work around
> is quite easy.
>
>>
>> However, as shown above, you will get an erroneous warning because it
>> just skips 1 cell and goes to the next to handle the case where the
>> phandle is optional and you want a fixed number of elements.
>
> Just for those reading along at home, with the one warning disabled, the
> messages become:
>
>    $  dtc -Wno-interrupts_property socfpga_arria10_socdk_sdmmc_ghrd_ovl_ext_cfg.dts >junk.dtb
>    <stdout>: Warning (unit_address_vs_reg): Node /fragment@0 has a unit name, but no reg property
>    <stdout>: Warning (unit_address_vs_reg): Node /fragment@0/__overlay__ has a reg or ranges property, but no unit name
>
>
>> I guess we can't validate overlays which is unfortunate. I don't think
>> that's a solvable problem unless you have the base DT.
>
> Yes, maybe.  But there are still some useful warnings for overlays, maybe.  I'm
> not sure what the implications of the "range_format" warning that I will show
> below are (I'd actually have to spend a few minutes thinking about ranges, and
> I don't have the cycles right now).
>
>
>>
>>> You can avoid the problem in your example dts with "-Wno-interrupts_property"
>>>
>>>   dtc -Wno-interrupts_property fpga_01_a.dts
>>>
>>> The larger set of other checks that might trigger the assert is too large
>>> for me to want to add "-Wno-" flags for all of them to the command line
>>> (as temporary workarounds).
>>
>> David thought more switches were better.
>
> Yep.  Not a complaint, just an observation about a _temporary_ workaround.
>
>
>>
>> Rob
>>
>
>
> Here is the "range_format" warning I mentioned above.  The dts file that
> started this thread hand crafts what is internal overlay data, which
> should be generated by the dtc compiler instead of being hand coded in
> the dts.  If I remove the hand coded stuff and let dtc generate the
> internal overlay data, the dtc messages become (use a wide window to
> avoid line wrapping):
>
> $ dtc -Wno-interrupts_property fpga_01_a.dts >junk.dtb
> <stdout>: Warning (ranges_format): "ranges" property in /fragment@0/__overlay__ has invalid length (32 bytes) (parent #address-cells == 2, child #address-cells == 2, #size-cells == 1)
> <stdout>: Warning (unit_address_vs_reg): Node /fragment@0 has a unit name, but no reg property
> <stdout>: Warning (unit_address_vs_reg): Node /fragment@0/__overlay__ has a reg or ranges property, but no unit name
> <stdout>: Warning (avoid_default_addr_size): Relying on default #address-cells value for /fragment@0/__overlay__
> <stdout>: Warning (avoid_default_addr_size): Relying on default #size-cells value for /fragment@0/__overlay__
>
>
> The second through last warning are about the format of the internal
> data structure, and hopefully could just be suppressed.  I don't
> know how easy or hard that would be to implement - I am very much
> not a dtc internals expert.
>
> The first warning says something about what the overlay source dts
> contains.  Here is what the original dts source looks like when
> transformed to not contain the hand crafted internal overlay data:
>
> $ cat fpga_01_a.dts
> /dts-v1/;
> /plugin/;
>
> // This assumes an existing label in the base dts
> // whose location is "/soc/base_fpga_region"
> &fpga_region {
>
>                         ranges = <0x00000000 0x00000000 0xc0000000 0x00040000>,
>                                  <0x00000001 0x00000000 0xff200000 0x00001000>;
>
>                         external-fpga-config;
>
>                         #address-cells = <2>;
>                         #size-cells = <1>;
>
>                         fpga_pr_region0 {
>                                 compatible = "fpga-region";
>                                 fpga-bridges = <&freeze_controller_0>;
>                                 ranges;
>                         };
>
>                         freeze_controller_0: freeze_controller@100000450 {
>                                 compatible = "altr,freeze-bridge-controller";
>                                 reg = <0x00000001 0x00000450 0x00000010>;
>                                 interrupt-parent = <&intc>;  /* <-- remove to fix build */
>                                 interrupts = <0 21 4>;
>                         };
> };
>
> Of course, if this was a real transformation, I would remove all the
> extra tabbing.  But the current form makes it easier to see that all
> of the stuff that is highly indented is unchanged from the original
> dts file.
>
> $ diff -u socfpga_arria10_socdk_sdmmc_ghrd_ovl_ext_cfg.dts fpga_01_a.dts
> --- socfpga_arria10_socdk_sdmmc_ghrd_ovl_ext_cfg.dts    2017-10-18 15:18:43.123137508 -0700
> +++ fpga_01_a.dts       2017-10-18 15:18:11.587136897 -0700
> @@ -1,12 +1,10 @@
>  /dts-v1/;
>  /plugin/;
> -/ {
> -       fragment@0 {
> -               target-path = "/soc/base_fpga_region";
> -               #address-cells = <1>;
> -               #size-cells = <1>;
>
> -               __overlay__ {
> +// This assumes an existing label in the base dts
> +// whose location is "/soc/base_fpga_region"
> +&fpga_region {
> +

Frank,

Thanks for correcting me on this.  I have this documented wrong in
Documentation/devicetree/bindings/fpga/fpga-region.txt
so I'll need to fix that to not steer people wrong.

Alan


>                         ranges = <0x00000000 0x00000000 0xc0000000 0x00040000>,
>                                  <0x00000001 0x00000000 0xff200000 0x00001000>;
>
> @@ -27,6 +25,4 @@
>                                 interrupt-parent = <&intc>;  /* <-- remove to fix build */
>                                 interrupts = <0 21 4>;
>                         };
> -               };
> -       };
>  };
>
>
> -Frank

Re: dtc issue with overlays starting in next-20171009

[Frank Rowand]

On 10/19/17 07:29, Alan Tull wrote:
> On Wed, Oct 18, 2017 at 5:34 PM, Frank Rowand <frowand.list@gmail.com> wrote:
>> On 10/18/17 13:16, Rob Herring wrote:
>>> Use devicetree-compiler list for dtc issues please.
>>>
>>> On Wed, Oct 18, 2017 at 2:33 PM, Frank Rowand <frowand.list@gmail.com> wrote:
>>>> Hi Rob, Alan,
>>>>
>>>> On 10/18/17 08:58, Alan Tull wrote:
>>>>> Hi Rob,
>>>>>
>>>>> I've noticed a problem compiling DT overlays and traced it back to
>>>>> beginning in next-20171009
>>>>>
>>>>> That tag adds the following in scripts/dtc
>>>>>
>>>>> e9480c1 2017-10-09 16:17:32 +0100 : Mark Brown : Merge remote-tracking
>>>>> branch 'devicetree/for-next'
>>>>> 4201d05 2017-10-03 15:03:47 -0500 : Rob Herring : scripts/dtc: Update
>>>>> to upstream version v1.4.5-3-gb1a60033c110
>>>>> 4322323 2017-10-03 15:03:46 -0500 : Rob Herring : scripts/dtc: add
>>>>> fdt_overlay.c and fdt_addresses.c to sync script
>>>>>
>>>>> The error is:
>>>>>
>>>>> dtc: /home/atull/repos/linux-socfpga/scripts/dtc/livetree.c:543:
>>>>> get_node_by_phandle: Assertion `(phandle != 0) && (phandle != -1)'
>>>>> failed.
>>>>> arch/arm/boot/dts/socfpga_overlay.dtb: Warning (clocks_property):
>>>>> Could not get phandle node for
>>>>> /fragment@0/__overlay__/gpio@10040:clocks(cell 0)
>>>>> Aborted (core dumped)
>>>>> scripts/Makefile.lib:316: recipe for target
>>>>> 'arch/arm/boot/dts/socfpga_arria10_socdk_sdmmc_ghrd_ovl_ext_cfg.dtb'
>>>>> failed
>>>>> make[2]: *** [arch/arm/boot/dts/socfpga_arria10_socdk_sdmmc_ghrd_ovl_ext_cfg.dtb]
>>>>> Error 134
>>>>> arch/arm/Makefile:346: recipe for target 'dtbs' failed
>>>>>
>>>>> Here's a simplified overlay that gets this error.  Taking out the line
>>>>> "interrupt-parent = <&intc>;" fixes the build.
>>>>>
>>>>> /dts-v1/;
>>>>> /plugin/;
>>>>> / {
>>>>>         fragment@0 {
>>>>>                 target-path = "/soc/base_fpga_region";
>>>>>                 #address-cells = <1>;
>>>>>                 #size-cells = <1>;
>>>>>
>>>>>                 __overlay__ {
>>>>>                         ranges = <0x00000000 0x00000000 0xc0000000 0x00040000>,
>>>>>                                  <0x00000001 0x00000000 0xff200000 0x00001000>;
>>>>>
>>>>>                         external-fpga-config;
>>>>>
>>>>>                         #address-cells = <2>;
>>>>>                         #size-cells = <1>;
>>>>>
>>>>>                         fpga_pr_region0 {
>>>>>                                 compatible = "fpga-region";
>>>>>                                 fpga-bridges = <&freeze_controller_0>;
>>>>>                                 ranges;
>>>>>                         };
>>>>>
>>>>>                         freeze_controller_0: freeze_controller@0x100000450 {
>>>>>                                 compatible = "altr,freeze-bridge-controller";
>>>>>                                 reg = <0x00000001 0x00000450 0x00000010>;
>>>>>                                 interrupt-parent = <&intc>;  /* <--
>>>>> remove to fix build */
>>>>>                                 interrupts = <0 21 4>;
>>>>>                         };
>>>>>                 };
>>>>>         };
>>>>> };
>>>>>
>>>>> Alan
>>>>
>>>> Phandle references in overlays are assigned the value of -1 (0xffffffff) in
>>>> the dtb, to be fixed up when loaded.  A new check sees this value and
>>>> triggers the assert.
>>>>
>>>> It is this commit in the upstream dtc tools tree:
>>>>
>>>>    commit ee3d26f6960bb5922d9a35fe266d9eac74a78ec0
>>>>    checks: add interrupts property check
>>>>
>>>> There are a bunch of other new checks that call get_node_by_phandle(),
>>>> and thus could trigger the assertion.
>>>>
>>>> I'm guessing that those checks would also trigger the assert if an
>>>> overlay contained something that would lead to one of the other checks
>>>> being processed.
>>>
>>> You won't get an assert because I check for 0 or -1 and skip the check
>>> in those cases. The interrupts check missed that condition.
>>
>> Awesome, thank for confirming that.  That means the temporary work around
>> is quite easy.
>>
>>>
>>> However, as shown above, you will get an erroneous warning because it
>>> just skips 1 cell and goes to the next to handle the case where the
>>> phandle is optional and you want a fixed number of elements.
>>
>> Just for those reading along at home, with the one warning disabled, the
>> messages become:
>>
>>    $  dtc -Wno-interrupts_property socfpga_arria10_socdk_sdmmc_ghrd_ovl_ext_cfg.dts >junk.dtb
>>    <stdout>: Warning (unit_address_vs_reg): Node /fragment@0 has a unit name, but no reg property
>>    <stdout>: Warning (unit_address_vs_reg): Node /fragment@0/__overlay__ has a reg or ranges property, but no unit name
>>
>>
>>> I guess we can't validate overlays which is unfortunate. I don't think
>>> that's a solvable problem unless you have the base DT.
>>
>> Yes, maybe.  But there are still some useful warnings for overlays, maybe.  I'm
>> not sure what the implications of the "range_format" warning that I will show
>> below are (I'd actually have to spend a few minutes thinking about ranges, and
>> I don't have the cycles right now).
>>
>>
>>>
>>>> You can avoid the problem in your example dts with "-Wno-interrupts_property"
>>>>
>>>>   dtc -Wno-interrupts_property fpga_01_a.dts
>>>>
>>>> The larger set of other checks that might trigger the assert is too large
>>>> for me to want to add "-Wno-" flags for all of them to the command line
>>>> (as temporary workarounds).
>>>
>>> David thought more switches were better.
>>
>> Yep.  Not a complaint, just an observation about a _temporary_ workaround.
>>
>>
>>>
>>> Rob
>>>
>>
>>
>> Here is the "range_format" warning I mentioned above.  The dts file that
>> started this thread hand crafts what is internal overlay data, which
>> should be generated by the dtc compiler instead of being hand coded in
>> the dts.  If I remove the hand coded stuff and let dtc generate the
>> internal overlay data, the dtc messages become (use a wide window to
>> avoid line wrapping):
>>
>> $ dtc -Wno-interrupts_property fpga_01_a.dts >junk.dtb
>> <stdout>: Warning (ranges_format): "ranges" property in /fragment@0/__overlay__ has invalid length (32 bytes) (parent #address-cells == 2, child #address-cells == 2, #size-cells == 1)
>> <stdout>: Warning (unit_address_vs_reg): Node /fragment@0 has a unit name, but no reg property
>> <stdout>: Warning (unit_address_vs_reg): Node /fragment@0/__overlay__ has a reg or ranges property, but no unit name
>> <stdout>: Warning (avoid_default_addr_size): Relying on default #address-cells value for /fragment@0/__overlay__
>> <stdout>: Warning (avoid_default_addr_size): Relying on default #size-cells value for /fragment@0/__overlay__
>>
>>
>> The second through last warning are about the format of the internal
>> data structure, and hopefully could just be suppressed.  I don't
>> know how easy or hard that would be to implement - I am very much
>> not a dtc internals expert.
>>
>> The first warning says something about what the overlay source dts
>> contains.  Here is what the original dts source looks like when
>> transformed to not contain the hand crafted internal overlay data:
>>
>> $ cat fpga_01_a.dts
>> /dts-v1/;
>> /plugin/;
>>
>> // This assumes an existing label in the base dts
>> // whose location is "/soc/base_fpga_region"
>> &fpga_region {
>>
>>                         ranges = <0x00000000 0x00000000 0xc0000000 0x00040000>,
>>                                  <0x00000001 0x00000000 0xff200000 0x00001000>;
>>
>>                         external-fpga-config;
>>
>>                         #address-cells = <2>;
>>                         #size-cells = <1>;
>>
>>                         fpga_pr_region0 {
>>                                 compatible = "fpga-region";
>>                                 fpga-bridges = <&freeze_controller_0>;
>>                                 ranges;
>>                         };
>>
>>                         freeze_controller_0: freeze_controller@100000450 {
>>                                 compatible = "altr,freeze-bridge-controller";
>>                                 reg = <0x00000001 0x00000450 0x00000010>;
>>                                 interrupt-parent = <&intc>;  /* <-- remove to fix build */
>>                                 interrupts = <0 21 4>;
>>                         };
>> };
>>
>> Of course, if this was a real transformation, I would remove all the
>> extra tabbing.  But the current form makes it easier to see that all
>> of the stuff that is highly indented is unchanged from the original
>> dts file.
>>
>> $ diff -u socfpga_arria10_socdk_sdmmc_ghrd_ovl_ext_cfg.dts fpga_01_a.dts
>> --- socfpga_arria10_socdk_sdmmc_ghrd_ovl_ext_cfg.dts    2017-10-18 15:18:43.123137508 -0700
>> +++ fpga_01_a.dts       2017-10-18 15:18:11.587136897 -0700
>> @@ -1,12 +1,10 @@
>>  /dts-v1/;
>>  /plugin/;
>> -/ {
>> -       fragment@0 {
>> -               target-path = "/soc/base_fpga_region";
>> -               #address-cells = <1>;
>> -               #size-cells = <1>;
>>
>> -               __overlay__ {
>> +// This assumes an existing label in the base dts
>> +// whose location is "/soc/base_fpga_region"
>> +&fpga_region {
>> +
> 
> Frank,
> 
> Thanks for correcting me on this.  I have this documented wrong in
> Documentation/devicetree/bindings/fpga/fpga-region.txt
> so I'll need to fix that to not steer people wrong.

Thanks for pointing that out.  The new devicetree source format
won't be available until the new dtc that is in Rob's next
branch hits mainline.

-Frank


> Alan
> 
> 
>>                         ranges = <0x00000000 0x00000000 0xc0000000 0x00040000>,
>>                                  <0x00000001 0x00000000 0xff200000 0x00001000>;
>>
>> @@ -27,6 +25,4 @@
>>                                 interrupt-parent = <&intc>;  /* <-- remove to fix build */
>>                                 interrupts = <0 21 4>;
>>                         };
>> -               };
>> -       };
>>  };
>>
>>
>> -Frank
> 

Re: dtc issue with overlays starting in next-20171009

[David Gibson]

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On Wed, Oct 18, 2017 at 03:16:34PM -0500, Rob Herring wrote:
> Use devicetree-compiler list for dtc issues please.
> 
> On Wed, Oct 18, 2017 at 2:33 PM, Frank Rowand <frowand.list-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:
> > Hi Rob, Alan,
> >
> > On 10/18/17 08:58, Alan Tull wrote:
> >> Hi Rob,
> >>
> >> I've noticed a problem compiling DT overlays and traced it back to
> >> beginning in next-20171009
> >>
> >> That tag adds the following in scripts/dtc
> >>
> >> e9480c1 2017-10-09 16:17:32 +0100 : Mark Brown : Merge remote-tracking
> >> branch 'devicetree/for-next'
> >> 4201d05 2017-10-03 15:03:47 -0500 : Rob Herring : scripts/dtc: Update
> >> to upstream version v1.4.5-3-gb1a60033c110
> >> 4322323 2017-10-03 15:03:46 -0500 : Rob Herring : scripts/dtc: add
> >> fdt_overlay.c and fdt_addresses.c to sync script
> >>
> >> The error is:
> >>
> >> dtc: /home/atull/repos/linux-socfpga/scripts/dtc/livetree.c:543:
> >> get_node_by_phandle: Assertion `(phandle != 0) && (phandle != -1)'
> >> failed.
> >> arch/arm/boot/dts/socfpga_overlay.dtb: Warning (clocks_property):
> >> Could not get phandle node for
> >> /fragment@0/__overlay__/gpio@10040:clocks(cell 0)
> >> Aborted (core dumped)
> >> scripts/Makefile.lib:316: recipe for target
> >> 'arch/arm/boot/dts/socfpga_arria10_socdk_sdmmc_ghrd_ovl_ext_cfg.dtb'
> >> failed
> >> make[2]: *** [arch/arm/boot/dts/socfpga_arria10_socdk_sdmmc_ghrd_ovl_ext_cfg.dtb]
> >> Error 134
> >> arch/arm/Makefile:346: recipe for target 'dtbs' failed
> >>
> >> Here's a simplified overlay that gets this error.  Taking out the line
> >> "interrupt-parent = <&intc>;" fixes the build.
> >>
> >> /dts-v1/;
> >> /plugin/;
> >> / {
> >>         fragment@0 {
> >>                 target-path = "/soc/base_fpga_region";
> >>                 #address-cells = <1>;
> >>                 #size-cells = <1>;
> >>
> >>                 __overlay__ {
> >>                         ranges = <0x00000000 0x00000000 0xc0000000 0x00040000>,
> >>                                  <0x00000001 0x00000000 0xff200000 0x00001000>;
> >>
> >>                         external-fpga-config;
> >>
> >>                         #address-cells = <2>;
> >>                         #size-cells = <1>;
> >>
> >>                         fpga_pr_region0 {
> >>                                 compatible = "fpga-region";
> >>                                 fpga-bridges = <&freeze_controller_0>;
> >>                                 ranges;
> >>                         };
> >>
> >>                         freeze_controller_0: freeze_controller@0x100000450 {
> >>                                 compatible = "altr,freeze-bridge-controller";
> >>                                 reg = <0x00000001 0x00000450 0x00000010>;
> >>                                 interrupt-parent = <&intc>;  /* <--
> >> remove to fix build */
> >>                                 interrupts = <0 21 4>;
> >>                         };
> >>                 };
> >>         };
> >> };
> >>
> >> Alan
> >
> > Phandle references in overlays are assigned the value of -1 (0xffffffff) in
> > the dtb, to be fixed up when loaded.  A new check sees this value and
> > triggers the assert.
> >
> > It is this commit in the upstream dtc tools tree:
> >
> >    commit ee3d26f6960bb5922d9a35fe266d9eac74a78ec0
> >    checks: add interrupts property check
> >
> > There are a bunch of other new checks that call get_node_by_phandle(),
> > and thus could trigger the assertion.
> >
> > I'm guessing that those checks would also trigger the assert if an
> > overlay contained something that would lead to one of the other checks
> > being processed.
> 
> You won't get an assert because I check for 0 or -1 and skip the check
> in those cases. The interrupts check missed that condition.
> 
> However, as shown above, you will get an erroneous warning because it
> just skips 1 cell and goes to the next to handle the case where the
> phandle is optional and you want a fixed number of elements.
> 
> I guess we can't validate overlays which is unfortunate. I don't think
> that's a solvable problem unless you have the base DT.

Right.  You can check some things in overlays, but when parsing
something requires information from the base tree, there is indeed not
much that can be done.

> > You can avoid the problem in your example dts with "-Wno-interrupts_property"
> >
> >   dtc -Wno-interrupts_property fpga_01_a.dts
> >
> > The larger set of other checks that might trigger the assert is too large
> > for me to want to add "-Wno-" flags for all of them to the command line
> > (as temporary workarounds).
> 
> David thought more switches were better.

Right, as a rule, I like fine configurability of the checks.

But.. there's a trick to make things easier to configure in batches:
when you enable a warning, you automatically enable all warnings that
warning has as prerequisites.  And when you disable a warning, every
other warning that has it as a prerequisite is also disabled.

So by adding some dummy checks with the right depencies, you can allow
enabling and disabling of groups of related checks with a single
command line option.

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson

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