GPMI iMX6ull timeout on DMA

[Christian Eggers]

On Monday, 29 July 2019, 08:41:51 CEST, Greg Ungerer wrote:
> Hi Miquel,
> 
> I am experiencing a problem with NAND flash DMA timeouts on
> iMX6ull based boards. The problem is very similar to that
> described in:
> 
>    https://linux-mtd.infradead.narkive.com/JIUulfFB/gpmi-imx6ull-timeout-on-dma
> 
> That didn't come to any specific resolution that I could see
> in that thread.

Hi all,

I am joining this thread because I am also affected by this problem. I use
kernel 5.10.65-rt53 but I have seen this issue on many previous versions. In the
past I only recognized this on my development setup but now this has been found
by our testing team.

In our test setup we simply perform a reboot every 30s. After 5 to 200 cycles
the test stops due to this error.

The kernel version I use already includes:

> Han Xu <han.xu at nxp.com>
> mtd: rawnand: gpmi: Fix the random DMA timeout issue

Additionally I tried ...

> Michael Trimarchi <michael at amarulasolutions.com>
> mtd: nand: Calculate the clock before enable it

... but the problem still persists.

In my case, some registers show different values (annotated below):

> 
> The boot trace on the console for me looks like this:
> 
> nand: device found, Manufacturer ID: 0x2c, Chip ID: 0xda
  nand: device found, Manufacturer ID: 0x2c, Chip ID: 0xdc
> nand: Micron MT29F2G08ABAEAWP
  nand: Micron MT29F4G08ABADAH4
> nand: 256 MiB, SLC, erase size: 128 KiB, page size: 2048, OOB size: 64
> gpmi-nand 1806000.gpmi-nand: DMA timeout, last DMA
> gpmi-nand 1806000.gpmi-nand: Show GPMI registers :
> gpmi-nand 1806000.gpmi-nand: offset 0x000 : 0x20830002
> gpmi-nand 1806000.gpmi-nand: offset 0x010 : 0x00000000
> gpmi-nand 1806000.gpmi-nand: offset 0x020 : 0x00000000
> gpmi-nand 1806000.gpmi-nand: offset 0x030 : 0x00000000
> gpmi-nand 1806000.gpmi-nand: offset 0x040 : 0x00000000
> gpmi-nand 1806000.gpmi-nand: offset 0x050 : 0x00000000
> gpmi-nand 1806000.gpmi-nand: offset 0x060 : 0x01c6800c
> gpmi-nand 1806000.gpmi-nand: offset 0x070 : 0x00010101
> gpmi-nand 1806000.gpmi-nand: offset 0x080 : 0xe0000000
> gpmi-nand 1806000.gpmi-nand: offset 0x090 : 0x23023336
> gpmi-nand 1806000.gpmi-nand: offset 0x0a0 : 0x000001ee
> gpmi-nand 1806000.gpmi-nand: offset 0x0b0 : 0xff000001
> gpmi-nand 1806000.gpmi-nand: offset 0x0c0 : 0x00000001
  gpmi-nand 1806000.nand-controller: offset 0x0c0 : 0x00000202
> gpmi-nand 1806000.gpmi-nand: offset 0x0d0 : 0x05020000
> gpmi-nand 1806000.gpmi-nand: Show BCH registers :
> gpmi-nand 1806000.gpmi-nand: offset 0x000 : 0x00000100
  gpmi-nand 1806000.nand-controller: offset 0x000 : 0x00000000
> gpmi-nand 1806000.gpmi-nand: offset 0x010 : 0x00000010
> gpmi-nand 1806000.gpmi-nand: offset 0x020 : 0x00000000
> gpmi-nand 1806000.gpmi-nand: offset 0x030 : 0x00000000
> gpmi-nand 1806000.gpmi-nand: offset 0x040 : 0x00000000
> gpmi-nand 1806000.gpmi-nand: offset 0x050 : 0x00000000
> gpmi-nand 1806000.gpmi-nand: offset 0x060 : 0x00000000
> gpmi-nand 1806000.gpmi-nand: offset 0x070 : 0x00000000
> gpmi-nand 1806000.gpmi-nand: offset 0x080 : 0x030a2080
  gpmi-nand 1806000.nand-controller: offset 0x080 : 0x070a4080
> gpmi-nand 1806000.gpmi-nand: offset 0x090 : 0x083e2080
  gpmi-nand 1806000.nand-controller: offset 0x090 : 0x10da4080
> gpmi-nand 1806000.gpmi-nand: offset 0x0a0 : 0x070a4080
> gpmi-nand 1806000.gpmi-nand: offset 0x0b0 : 0x10da4080
> gpmi-nand 1806000.gpmi-nand: offset 0x0c0 : 0x070a4080
> gpmi-nand 1806000.gpmi-nand: offset 0x0d0 : 0x10da4080
> gpmi-nand 1806000.gpmi-nand: offset 0x0e0 : 0x070a4080
> gpmi-nand 1806000.gpmi-nand: offset 0x0f0 : 0x10da4080
> gpmi-nand 1806000.gpmi-nand: offset 0x100 : 0x00000000
> gpmi-nand 1806000.gpmi-nand: offset 0x110 : 0x00000000
> gpmi-nand 1806000.gpmi-nand: offset 0x120 : 0x00000000
> gpmi-nand 1806000.gpmi-nand: offset 0x130 : 0x00000000
> gpmi-nand 1806000.gpmi-nand: offset 0x140 : 0x00000000
> gpmi-nand 1806000.gpmi-nand: offset 0x150 : 0x20484342
> gpmi-nand 1806000.gpmi-nand: offset 0x160 : 0x01000000
> gpmi-nand 1806000.gpmi-nand: offset 0x170 : 0x00000000
> gpmi-nand 1806000.gpmi-nand: BCH Geometry :
> GF length              : 13
> ECC Strength           : 8
> Page Size in Bytes     : 2110
> Metadata Size in Bytes : 10
> ECC Chunk0 Size in Bytes: 512
> ECC Chunkn Size in Bytes: 512
  ECC Chunk Size in Bytes: 512
> ECC Chunk Count        : 4
> Payload Size in Bytes  : 2048
> Auxiliary Size in Bytes: 16
> Auxiliary Status Offset: 12
> Block Mark Byte Offset : 1999
> Block Mark Bit Offset  : 0

Please let me know if further information is required.

regards
Christian