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

[Ulf Hansson]

On Thu, 30 Nov 2023 at 14:24, Jorge Ramirez-Ortiz, Foundries
<jorge@xxxxxxxxxxxx> wrote:
>
> On 30/11/23 11:34:18, Ulf Hansson wrote:
> > On Wed, 29 Nov 2023 at 17:05, Jorge Ramirez-Ortiz <jorge@xxxxxxxxxxxx> 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.

Well, I suggest we try to get some help from the driver authors then.

>
>
> > 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?

Good question. I think we should have an mmc_test for that, but I
don't think we have.

Unfortunately, I don't have the bandwidth to help with this currently,
so unless some other can step in and help you are on your own.

>
> >
> > 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
>
> Also I instrumented sdhci-of-arasan.c to confirm that tuning wasn't failing.
>
> diff --git a/drivers/mmc/host/sdhci-of-arasan.c b/drivers/mmc/host/sdhci-of-arasan.c
> index 681ac4cab8ab..54cde79d2719 100644
> --- a/drivers/mmc/host/sdhci-of-arasan.c
> +++ b/drivers/mmc/host/sdhci-of-arasan.c
> @@ -1123,7 +1123,10 @@ static int arasan_zynqmp_execute_tuning(struct mmc_host *mmc, u32 opcode)
>
>         err = sdhci_execute_tuning(mmc, opcode);
>         if (err)
> -           return err;
> +         WARN_ON(1);
> +
> + if (host->tuning_err)
> +         WARN_ON(1);
>
>         arasan_zynqmp_dll_reset(host, device_id);
>
>
> Incidentally - not sure if it is intentional or not - I noticed that the
> function arasan_zynqmp_execute_tuning(..) can not fail which seems wrong
> (IMO it should also check host->tuning_err and not only err which will
> always be 0).
>
> Do you think this needs fixing even though not related to this problem?

I usually defer to driver authors and Adrian as the SDHCI maintainer
for questions like these, so again, sorry for not being able to help
more than this.

[...]

Kind regards
Uffe