[PATCH] staging: axis-fifo: fix alignment and add DT binding documentation

[PATCH] staging: axis-fifo: fix alignment and add DT binding documentation

[Alexandru Hossu]

[-- Attachment #1: Type: text/plain, Size: 171 bytes --]

Add YAML device tree binding documentation for the Xilinx
AXI-Stream FIFO IP core and fix code alignment issue.

Signed-off-by: Alexandru Hossu <hossu.alexandru@gmail.com>

[-- Attachment #2: 0001-staging-axis-fifo-fix-alignment-and-add-DT-binding-d.patch --]
[-- Type: text/plain, Size: 3453 bytes --]

From b94514738af787173717cbfa85637c53084284da Mon Sep 17 00:00:00 2001
From: Alexandru Hossu <hossu.alexandru@gmail.com>
Date: Wed, 4 Mar 2026 12:06:49 +0100
Subject: [PATCH] staging: axis-fifo: fix alignment and add DT binding
 documentation

Signed-off-by: Alexandru Hossu <hossu.alexandru@gmail.com>
---
 .../bindings/misc/xlnx,axi-fifo-mm-s.yaml     | 77 +++++++++++++++++++
 drivers/staging/axis-fifo/axis-fifo.c         |  5 +-
 2 files changed, 81 insertions(+), 1 deletion(-)
 create mode 100644 Documentation/devicetree/bindings/misc/xlnx,axi-fifo-mm-s.yaml

diff --git a/Documentation/devicetree/bindings/misc/xlnx,axi-fifo-mm-s.yaml b/Documentation/devicetree/bindings/misc/xlnx,axi-fifo-mm-s.yaml
new file mode 100644
index 000000000..6d1cd651e
--- /dev/null
+++ b/Documentation/devicetree/bindings/misc/xlnx,axi-fifo-mm-s.yaml
@@ -0,0 +1,77 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/misc/xlnx,axi-fifo-mm-s.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Xilinx AXI-Stream FIFO
+
+description: |
+  The Xilinx AXI-Stream FIFO IP core has read and write AXI-Stream FIFOs,
+  the contents of which can be accessed from the AXI4 memory-mapped interface.
+  Currently supports only store-forward mode with a 32-bit AXI4-Lite interface.
+
+maintainers:
+  - Jolly Shah <jollys@xilinx.com>
+
+properties:
+  compatible:
+    enum:
+      - xlnx,axi-fifo-mm-s-4.1
+      - xlnx,axi-fifo-mm-s-4.2
+      - xlnx,axi-fifo-mm-s-4.3
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  interrupt-names:
+    items:
+      - const: interrupt
+
+  interrupt-parent: true
+
+  xlnx,use-rx-data:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    enum: [0, 1]
+    description: Set to 1 if RX FIFO is enabled, 0 otherwise.
+
+  xlnx,use-tx-data:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    enum: [0, 1]
+    description: Set to 1 if TX FIFO is enabled, 0 otherwise.
+
+  xlnx,rx-fifo-depth:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description: Depth of RX FIFO in words.
+
+  xlnx,tx-fifo-depth:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description: Depth of TX FIFO in words.
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - interrupt-names
+  - interrupt-parent
+  - xlnx,use-rx-data
+  - xlnx,use-tx-data
+
+additionalProperties: true
+
+examples:
+  - |
+    axi_fifo_mm_s_0: axi_fifo_mm_s@43c00000 {
+      compatible = "xlnx,axi-fifo-mm-s-4.1";
+      interrupt-names = "interrupt";
+      interrupt-parent = <&intc>;
+      interrupts = <0 29 4>;
+      reg = <0x43c00000 0x10000>;
+      xlnx,use-rx-data = <0x0>;
+      xlnx,use-tx-data = <0x1>;
+      xlnx,rx-fifo-depth = <0x200>;
+      xlnx,tx-fifo-depth = <0x8000>;
+    };
diff --git a/drivers/staging/axis-fifo/axis-fifo.c b/drivers/staging/axis-fifo/axis-fifo.c
index aa90b2719..6ca2bf4d4 100644
--- a/drivers/staging/axis-fifo/axis-fifo.c
+++ b/drivers/staging/axis-fifo/axis-fifo.c
@@ -245,8 +245,11 @@ static ssize_t axis_fifo_write(struct file *f, const char __user *buf,
 	} else {
 		mutex_lock(&fifo->write_lock);
 
+		u32 free_space;
+
+		free_space = ioread32(fifo->base_addr + XLLF_TDFV_OFFSET);
 		ret = wait_event_interruptible(fifo->write_queue,
-			ioread32(fifo->base_addr + XLLF_TDFV_OFFSET) >= words_to_write);
+						       free_space >= words_to_write);
 		if (ret)
 			goto end_unlock;
 	}
-- 
2.43.0

Re: [PATCH] staging: axis-fifo: fix alignment and add DT binding documentation

[Rob Herring (Arm)]

On Wed, 04 Mar 2026 12:08:53 +0100, Alexandru Hossu wrote:
> Add YAML device tree binding documentation for the Xilinx
> AXI-Stream FIFO IP core and fix code alignment issue.
> 
> Signed-off-by: Alexandru Hossu <hossu.alexandru@gmail.com>

My bot found errors running 'make dt_binding_check' on your patch:

yamllint warnings/errors:

dtschema/dtc warnings/errors:
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/misc/xlnx,axi-fifo-mm-s.yaml: properties: False schema does not allow True
	from schema $id: http://devicetree.org/meta-schemas/interrupts.yaml
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/misc/xlnx,axi-fifo-mm-s.example.dtb: axi_fifo_mm_s@43c00000 (xlnx,axi-fifo-mm-s-4.1): 'interrupt-parent' is a required property
	from schema $id: http://devicetree.org/schemas/misc/xlnx,axi-fifo-mm-s.yaml

doc reference errors (make refcheckdocs):

See https://patchwork.kernel.org/project/devicetree/patch/ae0a95f4-8dac-4690-8810-79ad5fee7895@gmail.com

The base for the series is generally the latest rc1. A different dependency
should be noted in *this* patch.

If you already ran 'make dt_binding_check' and didn't see the above
error(s), then make sure 'yamllint' is installed and dt-schema is up to
date:

pip3 install dtschema --upgrade

Please check and re-submit after running the above command yourself. Note
that DT_SCHEMA_FILES can be set to your schema file to speed up checking
your schema. However, it must be unset to test all examples with your schema.

Re: [PATCH] staging: axis-fifo: fix alignment and add DT binding documentation

[Krzysztof Kozlowski]

On 04/03/2026 12:08, Alexandru Hossu wrote:
> Add YAML device tree binding documentation for the Xilinx
> AXI-Stream FIFO IP core and fix code alignment issue.
> 
> Signed-off-by: Alexandru Hossu <hossu.alexandru@gmail.com>

No patch here. Please use b4 to post patches.

Please run scripts/checkpatch.pl on the patches and fix reported
warnings. After that, run also 'scripts/checkpatch.pl --strict' on the
patches and (probably) fix more warnings. Some warnings can be ignored,
especially from --strict run, but the code here looks like it needs a
fix. Feel free to get in touch if the warning is not clear.


Best regards,
Krzysztof

[PATCH v2] dt-bindings: misc: xlnx,axi-fifo-mm-s: fix interrupt-parent property

[Alexandru Hossu]

[-- Attachment #1: Type: text/plain, Size: 197 bytes --]

v2: Remove interrupt-parent property declaration as it is a standard
property that does not need to be explicitly defined in the binding.

Signed-off-by: Alexandru Hossu <hossu.alexandru@gmail.com>

[-- Attachment #2: 0001-dt-bindings-misc-xlnx-axi-fifo-mm-s-fix-interrupt-pa.patch --]
[-- Type: text/plain, Size: 1053 bytes --]

From 403c6c299c82c39dd09ed9ed75d6750d358e53da Mon Sep 17 00:00:00 2001
From: Alexandru Hossu <hossu.alexandru@gmail.com>
Date: Wed, 4 Mar 2026 13:43:09 +0100
Subject: [PATCH v2] dt-bindings: misc: xlnx,axi-fifo-mm-s: fix
 interrupt-parent property

Signed-off-by: Alexandru Hossu <hossu.alexandru@gmail.com>
---
 Documentation/devicetree/bindings/misc/xlnx,axi-fifo-mm-s.yaml | 2 --
 1 file changed, 2 deletions(-)

diff --git a/Documentation/devicetree/bindings/misc/xlnx,axi-fifo-mm-s.yaml b/Documentation/devicetree/bindings/misc/xlnx,axi-fifo-mm-s.yaml
index 6d1cd651e..a21cae6e6 100644
--- a/Documentation/devicetree/bindings/misc/xlnx,axi-fifo-mm-s.yaml
+++ b/Documentation/devicetree/bindings/misc/xlnx,axi-fifo-mm-s.yaml
@@ -31,7 +31,6 @@ properties:
     items:
       - const: interrupt
 
-  interrupt-parent: true
 
   xlnx,use-rx-data:
     $ref: /schemas/types.yaml#/definitions/uint32
@@ -56,7 +55,6 @@ required:
   - reg
   - interrupts
   - interrupt-names
-  - interrupt-parent
   - xlnx,use-rx-data
   - xlnx,use-tx-data
 
-- 
2.43.0

Re: [PATCH v2] dt-bindings: misc: xlnx,axi-fifo-mm-s: fix interrupt-parent property

[Krzysztof Kozlowski]

On 04/03/2026 13:46, Alexandru Hossu wrote:
> v2: Remove interrupt-parent property declaration as it is a standard
> property that does not need to be explicitly defined in the binding.
> 
> Signed-off-by: Alexandru Hossu <hossu.alexandru@gmail.com>


Stop and read the feedback.

There is still no patch!

Best regards,
Krzysztof

Re: [PATCH v2] dt-bindings: misc: xlnx,axi-fifo-mm-s: fix interrupt-parent property

[Krzysztof Kozlowski]

On 04/03/2026 13:51, Krzysztof Kozlowski wrote:
> On 04/03/2026 13:46, Alexandru Hossu wrote:
>> v2: Remove interrupt-parent property declaration as it is a standard
>> property that does not need to be explicitly defined in the binding.
>>
>> Signed-off-by: Alexandru Hossu <hossu.alexandru@gmail.com>
> 
> 
> Stop and read the feedback.
> 
> There is still no patch!

Look here:
https://lore.kernel.org/lkml/fbb68131-03ab-460b-8d11-e4892d91807f@gmail.com/
No patch inline, just separate attachment. That's not something possible
to review.

And another point is:
Do not attach (thread) your patchsets to some other threads (unrelated
or older versions). This buries them deep in the mailbox and might
interfere with applying entire sets. See also:
https://elixir.bootlin.com/linux/v6.16-rc2/source/Documentation/process/submitting-patches.rst#L830

Best regards,
Krzysztof

[PATCH] dt-bindings: misc: xlnx,axi-fifo-mm-s: fix interrupt-parent property

[Alexandru Hossu]

Signed-off-by: Alexandru Hossu <hossu.alexandru@gmail.com>
---
 .../devicetree/bindings/misc/xlnx,axi-fifo-mm-s.yaml   | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/Documentation/devicetree/bindings/misc/xlnx,axi-fifo-mm-s.yaml b/Documentation/devicetree/bindings/misc/xlnx,axi-fifo-mm-s.yaml
index 6d1cd651e..cdc295f2d 100644
--- a/Documentation/devicetree/bindings/misc/xlnx,axi-fifo-mm-s.yaml
+++ b/Documentation/devicetree/bindings/misc/xlnx,axi-fifo-mm-s.yaml
@@ -31,8 +31,6 @@ properties:
     items:
       - const: interrupt
 
-  interrupt-parent: true
-
   xlnx,use-rx-data:
     $ref: /schemas/types.yaml#/definitions/uint32
     enum: [0, 1]
@@ -56,7 +54,6 @@ required:
   - reg
   - interrupts
   - interrupt-names
-  - interrupt-parent
   - xlnx,use-rx-data
   - xlnx,use-tx-data
 
@@ -64,11 +61,16 @@ additionalProperties: true
 
 examples:
   - |
+    intc: interrupt-controller {
+      interrupt-controller;
+      #interrupt-cells = <1>;
+    };
+
     axi_fifo_mm_s_0: axi_fifo_mm_s@43c00000 {
       compatible = "xlnx,axi-fifo-mm-s-4.1";
       interrupt-names = "interrupt";
       interrupt-parent = <&intc>;
-      interrupts = <0 29 4>;
+      interrupts = <29>;
       reg = <0x43c00000 0x10000>;
       xlnx,use-rx-data = <0x0>;
       xlnx,use-tx-data = <0x1>;
-- 
2.43.0

Re: [PATCH] dt-bindings: misc: xlnx,axi-fifo-mm-s: fix interrupt-parent property

[Greg KH]

On Wed, Mar 04, 2026 at 02:16:10PM +0100, Alexandru Hossu wrote:
> Signed-off-by: Alexandru Hossu <hossu.alexandru@gmail.com>

For obvious reasons, we can't take patches without any changelog text,
nor would you want us to.

thanks,

greg k-h

Re: [PATCH] dt-bindings: misc: xlnx,axi-fifo-mm-s: fix interrupt-parent property

[Krzysztof Kozlowski]

On 04/03/2026 14:16, Alexandru Hossu wrote:
> Signed-off-by: Alexandru Hossu <hossu.alexandru@gmail.com>
> ---

NAK, I replied way too many times.

Best regards,
Krzysztof

Re: [PATCH] dt-bindings: misc: xlnx,axi-fifo-mm-s: fix interrupt-parent property

[Conor Dooley]

On 4 March 2026 13:22:48 GMT, Greg KH <gregkh@linuxfoundation.org> wrote:
>On Wed, Mar 04, 2026 at 02:16:10PM +0100, Alexandru Hossu wrote:
>> Signed-off-by: Alexandru Hossu <hossu.alexandru@gmail.com>
>
>For obvious reasons, we can't take patches without any changelog text,
>nor would you want us to.

This is also a second person working on this conversation.
I left commentary on the other version of it.
I am fairly confident that converting this binding is almost useless without evaluating whether this should become a dma engine.
I'm almost certain my employer has something very similar, based on naming and use case, and I saw no reason why it could not be a dma engine.
Any as-is conversation of this should, IMO, come with an evaluation of why this is the correct way to model it.
I don't think it's suitable for any sort of "internship" program that sees binding conversations as low hanging fruit.

Re: [PATCH] dt-bindings: misc: xlnx,axi-fifo-mm-s: fix interrupt-parent property

[Krzysztof Kozlowski]

On 04/03/2026 14:29, Conor Dooley wrote:
> 
> 
> On 4 March 2026 13:22:48 GMT, Greg KH <gregkh@linuxfoundation.org> wrote:
>> On Wed, Mar 04, 2026 at 02:16:10PM +0100, Alexandru Hossu wrote:
>>> Signed-off-by: Alexandru Hossu <hossu.alexandru@gmail.com>
>>
>> For obvious reasons, we can't take patches without any changelog text,
>> nor would you want us to.
> 
> This is also a second person working on this conversation.

I see, so that's a patch for something which does not exist yet (not
merged).

> I left commentary on the other version of it.
> I am fairly confident that converting this binding is almost useless without evaluating whether this should become a dma engine.
> I'm almost certain my employer has something very similar, based on naming and use case, and I saw no reason why it could not be a dma engine.
> Any as-is conversation of this should, IMO, come with an evaluation of why this is the correct way to model it.
> I don't think it's suitable for any sort of "internship" program that sees binding conversations as low hanging fruit.

Do you suspect another round of some GSoC or LFX mentorship?

Best regards,
Krzysztof

Re: [PATCH v2] dt-bindings: misc: xlnx,axi-fifo-mm-s: fix interrupt-parent property

[Dan Carpenter]

On Wed, Mar 04, 2026 at 01:46:00PM +0100, Alexandru Hossu wrote:
> v2: Remove interrupt-parent property declaration as it is a standard
> property that does not need to be explicitly defined in the binding.
> 
> Signed-off-by: Alexandru Hossu <hossu.alexandru@gmail.com>

Please, wait a day between resends.  No need to rush.

https://staticthinking.wordpress.com/2022/07/27/how-to-send-a-v2-patch/

regards,
dan carpenter

Re: [PATCH] dt-bindings: misc: xlnx,axi-fifo-mm-s: fix interrupt-parent property

[Conor Dooley]

[-- Attachment #1: Type: text/plain, Size: 2294 bytes --]

On Wed, Mar 04, 2026 at 03:08:46PM +0100, Krzysztof Kozlowski wrote:
> On 04/03/2026 14:29, Conor Dooley wrote:
> > 
> > 
> > On 4 March 2026 13:22:48 GMT, Greg KH <gregkh@linuxfoundation.org> wrote:
> >> On Wed, Mar 04, 2026 at 02:16:10PM +0100, Alexandru Hossu wrote:
> >>> Signed-off-by: Alexandru Hossu <hossu.alexandru@gmail.com>
> >>
> >> For obvious reasons, we can't take patches without any changelog text,
> >> nor would you want us to.
> > 
> > This is also a second person working on this conversation.
> 
> I see, so that's a patch for something which does not exist yet (not
> merged).

This is the usual "two people working independently", except
Alexandru's "v2" is actually not a v2 but rather a patch on top of his
own v1. Ditto with his v3. It's not a patch on top of the other guy.

> 
> > I left commentary on the other version of it.
> > I am fairly confident that converting this binding is almost useless without evaluating whether this should become a dma engine.
> > I'm almost certain my employer has something very similar, based on naming and use case, and I saw no reason why it could not be a dma engine.
> > Any as-is conversation of this should, IMO, come with an evaluation of why this is the correct way to model it.
> > I don't think it's suitable for any sort of "internship" program that sees binding conversations as low hanging fruit.

Whoops, my bad on the long lines, sent it from my phone..

> Do you suspect another round of some GSoC or LFX mentorship?

Yeah, that is my suspicion. Lucas (the other submitter) also displayed
lack of familiarity with the process, but that may just be happenstance.
Plenty of binding conversions I am sure are suitable for some sort of

"internship", but probably not ones in staging, since they probably need
to come with an evaluation of whether things are currently correct and
maybe with driver changes that really require having the hardware.

This is probably one of the few cases where what's in staging is a bad
candidate to work on, and things outside of staging that have a fixed
ABI are much easier to convert.

If this is some sort of "internship", probably the guidance on what to
do should not include binding conversions without oversight from the
mentor.

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 228 bytes --]