Re: GPMI iMX6ull timeout on DMA

Greg Ungerer
2019-08-09T05:21:23Z

Hi Boris,

On 9/8/19 2:36 am, Boris Brezillon wrote:
> On Mon, 5 Aug 2019 15:51:05 +1000
> Greg Ungerer <gerg@kernel.org> wrote:
>> On 2/8/19 10:51 pm, Boris Brezillon wrote:
>>> On Fri, 2 Aug 2019 22:34:57 +1000
>>> Greg Ungerer <gerg@kernel.org> wrote:
>>>> On 31/7/19 4:28 pm, Boris Brezillon wrote:
>>>>> On Wed, 31 Jul 2019 12:05:44 +1000
>>>>> Greg Ungerer <gerg@kernel.org> wrote:
>>>>>> On 30/7/19 6:38 pm, Miquel Raynal wrote:
>>>>>>> Greg Ungerer <gerg@kernel.org> wrote on Tue, 30 Jul 2019 16:06:55 +1000:
>>>>>>>> On 30/7/19 10:41 am, Greg Ungerer wrote:
>>>>>>>>> On 30/7/19 10:28 am, Greg Ungerer wrote:
>>>>>>>>>> On 29/7/19 10:47 pm, Miquel Raynal wrote:
>>>>>>>>>>> Greg Ungerer <gerg@kernel.org> wrote on Mon, 29 Jul 2019 22:33:56 +1000:
>>>>>>>>>>>> On 29/7/19 6:36 pm, Miquel Raynal wrote:
>>>>>>>>>>>>> Greg Ungerer <gerg@kernel.org> wrote on Mon, 29 Jul 2019 16:41:51 +1000:
>>>>>>>>> [snip]
>>>>>> Note that this was generated on a normal boot up (not failure).
>>>>>
>>>>> The values looks good. Can you try with the below diff applied?
>>>>> --->8---
>>>>> diff --git a/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c b/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c
>>>>> index 334fe3130285..9771f6a82abe 100644
>>>>> --- a/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c
>>>>> +++ b/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c
>>>>> @@ -721,12 +721,10 @@ static void gpmi_nfc_apply_timings(struct gpmi_nand_data *this)
>>>>> writel(hw->ctrl1n, gpmi_regs + HW_GPMI_CTRL1_SET);
>>>>>
>>>>> /* Wait 64 clock cycles before using the GPMI after enabling the DLL */
>>>>> - dll_wait_time_us = USEC_PER_SEC / hw->clk_rate * 64;
>>>>> - if (!dll_wait_time_us)
>>>>> - dll_wait_time_us = 1;
>>>>> + dll_wait_time_us = DIV_ROUND_UP(USEC_PER_SEC * 64, hw->clk_rate);
>>>>>
>>>>> /* Wait for the DLL to settle. */
>>>>> - udelay(dll_wait_time_us);
>>>>> + usleep_range(dll_wait_time_us, dll_wait_time_us * 10);
>>>>> }
>>>>>
>>>>> static int gpmi_setup_data_interface(struct nand_chip *chip, int chipnr,
>>>>
>>>> Eventually it failed, in the same way with with same errors.
>>>> Took quite a while, over 600 boot cycles.
>>>>
>>>> Note also that I had to hand merge the changes, since in 5.1.14 that
>>>> gpmi_nfc_apply_timings() is in gpmi-lib.c. But it was trivial to do.
>>>
>>> Oh well. I guess the next thing to do would be to dump the timing regs
>>> and clk rate that are set by the bootloader (before the driver override
>>> them) or those applied by an older kernel (one that didn't have that
>>> issue).
>>
>> Is this useful?
>
> Hm, looks like it's configured in mode 0, so no, it's not super useful.
> Can you try booting an older kernel (one that didn't have the
> ->setup_data_interface() hook implemented).

Ok. I went back from 5.1 and the first kernel I could find that
returned no grep hits for "setup_data_interface" was 4.16.

So I built for my target with that and added similar trace to dump
the hardware register settings for that. Debug output looks like
this now for it:

...
drivers/mtd/nand/gpmi-nand/gpmi-nand.c(807): gpmi_get_clks()
clk_get_rate(r->clock[0])=22000000
drivers/mtd/nand/gpmi-nand/gpmi-lib.c(1054): gpmi_begin()
HW_GPMI_TIMING0=0x00010203
HW_GPMI_TIMING1=0x05000000
nand: device found, Manufacturer ID: 0x2c, Chip ID: 0xda
nand: Micron MT29F2G08ABAEAWP
nand: 256 MiB, SLC, erase size: 128 KiB, page size: 2048, OOB size: 64
drivers/mtd/nand/gpmi-nand/gpmi-lib.c(966): enable_edo_mode()
clk_get_rate(r->clock[0])=99000000
gpmi-nand 1806000.gpmi-nand: enable the asynchronous EDO mode 5
drivers/mtd/nand/gpmi-nand/gpmi-lib.c(1054): gpmi_begin()
HW_GPMI_TIMING0=0x00010101
HW_GPMI_TIMING1=0x90000000
Scanning device for bad blocks
5 ofpart partitions found on MTD device gpmi-nand
Creating 5 MTD partitions on "gpmi-nand":
0x000000000000-0x000000500000 : "u-boot"
0x000000500000-0x000000600000 : "u-boot-env"
0x000000600000-0x000000800000 : "log"
0x000000800000-0x000010000000 : "flash"
0x000000000000-0x000010000000 : "all"
gpmi-nand 1806000.gpmi-nand: driver registered.
...

I am running boot tests now on this to confirm it actually runs
reliably.

Regards
Greg

>> With attached patch, I get the following dump of the timing
>> settings in use:
>>
>> ...
>> drivers/mtd/nand/raw/gpmi-nand/gpmi-lib.c(490): gpmi_nfc_apply_timings()
>> HW_GPMI_TIMING0=0x00010203 (calculated=0x00020101)
>> HW_GPMI_TIMING1=0x00000000 (calculated=0x60000000)
>> HW_GPMI_CTRL1_SET=0x01c4000c (calculated=0x00000000)
>> r->clock[0]=22000000 (calculated=22000000)
>> random: fast init done
>> nand: device found, Manufacturer ID: 0x2c, Chip ID: 0xda
>> nand: Micron MT29F2G08ABAEAWP
>> nand: 256 MiB, SLC, erase size: 128 KiB, page size: 2048, OOB size: 64
>> drivers/mtd/nand/raw/gpmi-nand/gpmi-lib.c(490): gpmi_nfc_apply_timings()
>> HW_GPMI_TIMING0=0x00010203 (calculated=0x00020101)
>> HW_GPMI_TIMING1=0x00000000 (calculated=0xb0000000)
>> HW_GPMI_CTRL1_SET=0x01c4000c (calculated=0x00000000)
>> r->clock[0]=22000000 (calculated=22000000)
>> drivers/mtd/nand/raw/gpmi-nand/gpmi-lib.c(490): gpmi_nfc_apply_timings()
>> HW_GPMI_TIMING0=0x00010203 (calculated=0x00010101)
>> HW_GPMI_TIMING1=0x00000000 (calculated=0xe0000000)
>> HW_GPMI_CTRL1_SET=0x01c4000c (calculated=0x00c28000)
>> r->clock[0]=22000000 (calculated=100000000)
>> Scanning device for bad blocks
>> 5 fixed-partitions partitions found on MTD device gpmi-nand
>> Creating 5 MTD partitions on "gpmi-nand":
>> 0x000000000000-0x000000500000 : "u-boot"
>> 0x000000500000-0x000000600000 : "u-boot-env"
>> 0x000000600000-0x000000800000 : "log"
>> 0x000000800000-0x000010000000 : "flash"
>> 0x000000000000-0x000010000000 : "all"
>> gpmi-nand 1806000.gpmi-nand: driver registered.
>> ...
>>
>> Regards
>> Greg
>>
>>