Re: GPMI iMX6ull timeout on DMA

[Greg Ungerer <gerg@kernel.org>]

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Hi Boris,

On 9/8/19 5:32 pm, Boris Brezillon wrote:
> On Fri, 9 Aug 2019 16:55:22 +1000
> Greg Ungerer <gerg@kernel.org> wrote:
>> On 9/8/19 4:23 pm, Boris Brezillon wrote:
>>> On Fri, 9 Aug 2019 15:20:52 +1000
>>> Greg Ungerer <gerg@kernel.org> wrote:
>>>> 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
>>>
>>> TIMING0 match the one you have with 5.1 kernels.
>>>    
>>>>      HW_GPMI_TIMING1=0x90000000
>>>
>>> And we even have a bigger timeout value in 5.1 (0xe0000000), so we
>>> should be all safe WRT to timings in TIMING{0,1}.
>>>
>>> Can you dump CTRL1?
>>
>> drivers/mtd/nand/gpmi-nand/gpmi-lib.c(1054): gpmi_begin()
>>     HW_GPMI_TIMING0=0x00010101
>>     HW_GPMI_TIMING1=0x90000000
>>     HW_GPMI_CTRL1_SET=0x01c4800c
> 
> The read/write delay fields seem to match, but there are a few more
> fields set in this version:
> - DECOUPLE_CS
> - BCH_MODE
> - DEV_RESET
> - CTRL1_ATA_IRQRDY_POLARITY__ACTIVEHIGH
> 
> Looks like those fields are not explicitly set in the gpmi_begin()
> patch, but maybe you dumped CTRL1. Would you mind sharing your patch?

Attached.


> If I'm right and you indeed dumped CTRL1, it might be worth doing the
> same in your 5.1 kernel so we can more easily compare those dumps.
> While at it, can you dump CTRL1 before and after applying the changes?

Will do. I am out of my lab for the weekend, but I'll get
those numbers first thing Monday morning.

Regards
Greg


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