Re: [PATCHv2] mmc: rpmb: add quirk MMC_QUIRK_BROKEN_RPMB_RETUNE

[Adrian Hunter <adrian.hunter@intel.com>]

On 1/12/23 09:40, Jorge Ramirez-Ortiz, Foundries wrote:
> On 30/11/23 23:19:45, Jorge Ramirez-Ortiz, Foundries wrote:
>> On 30/11/23 23:02:15, Jorge Ramirez-Ortiz, Foundries wrote:
>>> On 30/11/23 21:12:28, Adrian Hunter wrote:
>>>> On 30/11/23 15:24, Jorge Ramirez-Ortiz, Foundries wrote:
>>>>> On 30/11/23 11:34:18, Ulf Hansson wrote:
>>>>>> On Wed, 29 Nov 2023 at 17:05, Jorge Ramirez-Ortiz <jorge@foundries.io> wrote:
>>>>>>>
>>>>>>> On the eMMC SanDisk iNAND 7250 configured with HS200, requesting a
>>>>>>> re-tune before switching to the RPMB partition would randomly cause
>>>>>>> subsequent RPMB requests to fail with EILSEQ:
>>>>>>> * data error -84, tigggered in __mmc_blk_ioctl_cmd()
>>>>>>>
>>>>>>> This commit skips the retune when switching to RPMB.
>>>>>>> Tested over several days with per minute RPMB reads.
>>>>>>
>>>>>> This sounds weird to me and needs more testing/debugging in my
>>>>>> opinion, especially at the host driver level. Perhaps add some new
>>>>>> tests in mmc_test, that does a partition switch to/from any partition
>>>>>> and then run regular I/O again to see if the problem is easier to
>>>>>> reproduce?
>>>>>
>>>>> hi Uffe
>>>>>
>>>>> ok I'll have a look - I have never used this driver before, so if you
>>>>> have anything in the works I'll be glad to integrated and adapt.
>>>>>
>>>>>>
>>>>>> The point is, I wonder what is so special with RPMB here? Note that,
>>>>>> it has been quite common that host drivers/controllers have had issues
>>>>>> with their tuning support, so I would not be surprised if that is the
>>>>>> case here too.
>>>>>
>>>>> Right, it is just that the tuning function for of-arasan is the generic
>>>>> __sdhci_execute_tuning() - only wrapped around arasan DLL reset
>>>>> calls. Hence why I aimed for the card: __sdhci_execute_tuning and ZynqMP
>>>>> are not recent functions or architectures.
>>>>>
>>>>>
>>>>>> Certainly I would be surprised if the problem is at
>>>>>> the eMMC card side, but I may be wrong.
>>>>>
>>>>> How do maintainers test the tuning methods? is there anything else for
>>>>> me to do other than forcing a retune with different partitions?
>>>>>
>>>>>>
>>>>>> Kind regards
>>>>>> Uffe
>>>>>
>>>>> For completeness this is the error message - notice that we have a
>>>>> trusted application (fiovb) going through OP-TEE and back to the TEE
>>>>> supplicant issuing an rpmb read of a variable (pretty normal these days,
>>>>> we use it on many different platforms - ST, NXP, AMD/Xilinx, TI..).
>>>>>
>>>>> The issue on this Zynqmp platform is scarily simple to reproduce; you
>>>>> can ignore the OP-TEE trace, it is just the TEE way of reporting that
>>>>> the RPMB read failed.
>>>>>
>>>>> root@uz3cg-dwg-sec:/var/rootdirs/home/fio# fiovb_printenv m4hash
>>>>> [  461.775084] sdhci-arasan ff160000.mmc: __mmc_blk_ioctl_cmd: data error -84
>>>>> E/TC:? 0
>>>>> E/TC:? 0 TA panicked with code 0xffff0000
>>>>> E/LD:  Status of TA 22250a54-0bf1-48fe-8002-7b20f1c9c9b1
>>>>> E/LD:   arch: aarch64
>>>>> E/LD:  region  0: va 0xc0004000 pa 0x7e200000 size 0x002000 flags rw-s (ldelf)
>>>>> E/LD:  region  1: va 0xc0006000 pa 0x7e202000 size 0x008000 flags r-xs (ldelf)
>>>>> E/LD:  region  2: va 0xc000e000 pa 0x7e20a000 size 0x001000 flags rw-s (ldelf)
>>>>> E/LD:  region  3: va 0xc000f000 pa 0x7e20b000 size 0x004000 flags rw-s (ldelf)
>>>>> E/LD:  region  4: va 0xc0013000 pa 0x7e20f000 size 0x001000 flags r--s
>>>>> E/LD:  region  5: va 0xc0014000 pa 0x7e22c000 size 0x005000 flags rw-s (stack)
>>>>> E/LD:  region  6: va 0xc0019000 pa 0x816b31fc8 size 0x001000 flags rw-- (param)
>>>>> E/LD:  region  7: va 0xc001a000 pa 0x816aa1fc8 size 0x002000 flags rw-- (param)
>>>>> E/LD:  region  8: va 0xc006b000 pa 0x00001000 size 0x014000 flags r-xs [0]
>>>>> E/LD:  region  9: va 0xc007f000 pa 0x00015000 size 0x008000 flags rw-s [0]
>>>>> E/LD:   [0] 22250a54-0bf1-48fe-8002-7b20f1c9c9b1 @ 0xc006b000
>>>>> E/LD:  Call stack:
>>>>> E/LD:   0xc006de58
>>>>> E/LD:   0xc006b388
>>>>> E/LD:   0xc006ed40
>>>>> E/LD:   0xc006b624
>>>>> Read persistent value for m4hash failed: Exec format error
>>>>
>>>> Have you tried dynamic debug for mmc
>>>>
>>>>     Kernel must be configured:
>>>>
>>>>         CONFIG_DYNAMIC_DEBUG=y
>>>>
>>>>     To enable mmc debug via sysfs:
>>>>
>>>>         echo 'file drivers/mmc/core/* +p' > /sys/kernel/debug/dynamic_debug/control
>>>>         echo 'file drivers/mmc/host/* +p' > /sys/kernel/debug/dynamic_debug/control
>>>>
>>>>
>>>
>>> hi Adrian
>>>
>>> Sure, this is the output of the trace:
>>>
>>> [  422.018756] mmc0: sdhci: IRQ status 0x00000020
>>> [  422.018789] mmc0: sdhci: IRQ status 0x00000020
>>> [  422.018817] mmc0: sdhci: IRQ status 0x00000020
>>> [  422.018848] mmc0: sdhci: IRQ status 0x00000020
>>> [  422.018875] mmc0: sdhci: IRQ status 0x00000020
>>> [  422.018902] mmc0: sdhci: IRQ status 0x00000020
>>> [  422.018932] mmc0: sdhci: IRQ status 0x00000020
>>> [  422.020013] mmc0: sdhci: IRQ status 0x00000001
>>> [  422.020027] mmc0: sdhci: IRQ status 0x00000002
>>> [  422.020034] mmc0: req done (CMD6): 0: 00000800 00000000 00000000 00000000
>>> [  422.020054] mmc0: starting CMD13 arg 00010000 flags 00000195
>>> [  422.020068] mmc0: sdhci: IRQ status 0x00000001
>>> [  422.020076] mmc0: req done (CMD13): 0: 00000900 00000000 00000000 00000000
>>> [  422.020092] <mmc0: starting CMD23 arg 00000001 flags 00000015>
>>> [  422.020101] mmc0: starting CMD25 arg 00000000 flags 00000035
>>> [  422.020108] mmc0:     blksz 512 blocks 1 flags 00000100 tsac 400 ms nsac 0
>>> [  422.020124] mmc0: sdhci: IRQ status 0x00000001
>>> [  422.021671] mmc0: sdhci: IRQ status 0x00000002
>>> [  422.021691] mmc0: req done <CMD23>: 0: 00000000 00000000 00000000 00000000
>>> [  422.021700] mmc0: req done (CMD25): 0: 00000900 00000000 00000000 00000000
>>> [  422.021708] mmc0:     512 bytes transferred: 0
>>> [  422.021728] mmc0: starting CMD13 arg 00010000 flags 00000195
>>> [  422.021743] mmc0: sdhci: IRQ status 0x00000001
>>> [  422.021752] mmc0: req done (CMD13): 0: 00000900 00000000 00000000 00000000
>>> [  422.021771] <mmc0: starting CMD23 arg 00000001 flags 00000015>
>>> [  422.021779] mmc0: starting CMD18 arg 00000000 flags 00000035
>>> [  422.021785] mmc0:     blksz 512 blocks 1 flags 00000200 tsac 100 ms nsac 0
>>> [  422.021804] mmc0: sdhci: IRQ status 0x00000001
>>> [  422.022566] mmc0: sdhci: IRQ status 0x00208000 <---------------------------------- this doesnt seem right
>>> [  422.022629] mmc0: req done <CMD23>: 0: 00000000 00000000 00000000 00000000
>>> [  422.022639] mmc0: req done (CMD18): 0: 00000900 00000000 00000000 00000000
>>> [  422.022647] mmc0:     0 bytes transferred: -84 < --------------------------------- it should have transfered 4096 bytes
>>> [  422.022669] sdhci-arasan ff160000.mmc: __mmc_blk_ioctl_cmd: data error -84
>>> [  422.029619] mmc0: starting CMD6 arg 03b30001 flags 0000049d
>>> [  422.029636] mmc0: sdhci: IRQ status 0x00000001
>>> [  422.029652] mmc0: sdhci: IRQ status 0x00000002
>>> [  422.029660] mmc0: req done (CMD6): 0: 00000800 00000000 00000000 00000000
>>> [  422.029680] mmc0: starting CMD13 arg 00010000 flags 00000195
>>> [  422.029693] mmc0: sdhci: IRQ status 0x00000001
>>> [  422.029702] mmc0: req done (CMD13): 0: 00000900 00000000 00000000 00000000
>>> [  422.196996] <mmc0: starting CMD23 arg 00000400 flags 00000015>
>>> [  422.197051] mmc0: starting CMD25 arg 058160e0 flags 000000b5
>>> [  422.197079] mmc0:     blksz 512 blocks 1024 flags 00000100 tsac 400 ms nsac 0
>>> [  422.197110] mmc0:     CMD12 arg 00000000 flags 0000049d
>>> [  422.199455] mmc0: sdhci: IRQ status 0x00000020
>>> [  422.199526] mmc0: sdhci: IRQ status 0x00000020
>>> [  422.199585] mmc0: sdhci: IRQ status 0x00000020
>>> [  422.199641] mmc0: sdhci: IRQ status 0x00000020
>>> [  422.199695] mmc0: sdhci: IRQ status 0x00000020
>>> [  422.199753] mmc0: sdhci: IRQ status 0x00000020
>>> [  422.199811] mmc0: sdhci: IRQ status 0x00000020
>>> [  422.199865] mmc0: sdhci: IRQ status 0x00000020
>>> [  422.199919] mmc0: sdhci: IRQ status 0x00000020
>>> [  422.199972] mmc0: sdhci: IRQ status 0x00000020
>>> [  422.200026] mmc0: sdhci: IRQ status 0x00000020
>>>
>>>
>>> does this help?
> 
> Just asking because it doesn't mean much to me other than the obvious CRC
> problem.
> 
> Being this issue so easy to trigger - and to fix - indicates a problem
> on the card more than on the algorithm (otherwise faults would be all
> over the place). But I am not an expert on this area.
> 
> any additional suggestions welcome.

My guess is that sometimes tuning produces a "bad" result. Perhaps
the margins are very tight and the difference is only 1 tap.  When
a "bad" result happens in non-RPMB, a CRC error results in re-tuning
and retry, so no errors are seen.  When it happens in RPMB, that is
not possible, so the error is obvious.  Not re-tuning before RPMB
switch helps because the CRC-error->re-tuning to a "good" result has
probably already happened.

However,  based on that theory, it is not necessary the eMMC that is
at fault.

It may be worth considering a stronger eMMC driver strength setting.

sdhci supports err_stats in debugfs - that may show how many CRC
errors there are when not accessing RPMB.

I don't object to skipping re-tuning before RPMB switch, but I am
not sure about tying it to a specific eMMC.