Re: GPMI iMX6ull timeout on DMA

From: Greg Ungerer <gerg@kernel.org>
To: Boris Brezillon <boris.brezillon@collabora.com>
Cc: Miquel Raynal <miquel.raynal@bootlin.com>,
	s.hauer@pengutronix.de,
	Michael Nazzareno Trimarchi <michael@amarulasolutions.com>,
	linux-mtd@lists.infradead.org,
	Boris Brezillon <bbrezillon@kernel.org>
Subject: Re: GPMI iMX6ull timeout on DMA
Date: Fri, 9 Aug 2019 16:55:22 +1000	[thread overview]
Message-ID: <ce7157e2-a8d0-7204-4003-8a711acb65b8@kernel.org> (raw)
In-Reply-To: <20190809082356.0cf60555@collabora.com>


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
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.

Regards
Greg


>> 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.
>> ...
>>
> 
> 

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