Re: [PATCH] mmc: meson-mx-sdio: trigger a soft reset after a timeout or CRC error

From: Martin Blumenstingl
Date: Thu May 07 2020 - 17:15:02 EST


Hi Ulf,

On Thu, May 7, 2020 at 11:29 AM Ulf Hansson <ulf.hansson@xxxxxxxxxx> wrote:
>
> On Mon, 4 May 2020 at 00:28, Martin Blumenstingl
> <martin.blumenstingl@xxxxxxxxxxxxxx> wrote:
> >
> > The vendor driver (from the 3.10 kernel) triggers a soft reset every
> > time before starting a new command. While this fixes a problem where
> > SDIO cards are not detected at all (because all commands simply
> > timed out) this hurts SD card read performance a bit (in my tests
> > between 10% to 20%).
> >
> > Trigger a soft reset after we got a CRC error or if the previous command
> > timed out (just like the vendor driver from the same 3.10 kernel for the
> > newer SDHC controller IP does). This fixes detection of SDIO cards and
> > doesn't hurt SD card read performance at the same time.
> >
> > With this patch the initialization of an RTL8723BS SDIO card looks like
> > this:
> > req done (CMD52): -110: 00000000 00000000 00000000 00000000
> > clock 400000Hz busmode 2 powermode 2 cs 1 Vdd 21 width 1 timing 0
> > starting CMD0 arg 00000000 flags 000000c0
> > req done (CMD0): 0: 00000000 00000000 00000000 00000000
> > clock 400000Hz busmode 2 powermode 2 cs 0 Vdd 21 width 1 timing 0
> > starting CMD8 arg 000001aa flags 000002f5
> > req done (CMD8): -110: 00000000 00000000 00000000 00000000
> > starting CMD5 arg 00000000 flags 000002e1
> > req done (CMD5): 0: 90ff0000 00000000 00000000 00000000
> > starting CMD5 arg 00200000 flags 000002e1
> > req done (CMD5): 0: 90ff0000 00000000 00000000 00000000
> > starting CMD3 arg 00000000 flags 00000075
> > req done (CMD3): 0: 00010000 00000000 00000000 00000000
> > starting CMD7 arg 00010000 flags 00000015
> > req done (CMD7): 0: 00001e00 00000000 00000000 00000000
> > starting CMD52 arg 00000000 flags 00000195
> > req done (CMD52): 0: 00001032 00000000 00000000 00000000
> > [... more CMD52 omitted ...]
> > clock 400000Hz busmode 2 powermode 2 cs 0 Vdd 21 width 1 timing 2
> > clock 50000000Hz busmode 2 powermode 2 cs 0 Vdd 21 width 1 timing 2
> > starting CMD52 arg 00000e00 flags 00000195
> > req done (CMD52): 0: 00001000 00000000 00000000 00000000
> > starting CMD52 arg 80000e02 flags 00000195
> > req done (CMD52): 0: 00001002 00000000 00000000 00000000
> > clock 50000000Hz busmode 2 powermode 2 cs 0 Vdd 21 width 4 timing 2
> > starting CMD52 arg 00020000 flags 00000195
> > req done (CMD52): 0: 00001007 00000000 00000000 00000000
> > [... more CMD52 omitted ...]
> > new high speed SDIO card at address 0001
> >
> > Fixes: ed80a13bb4c4c9 ("mmc: meson-mx-sdio: Add a driver for the Amlogic Meson8 and Meson8b SoCs")
> > Signed-off-by: Martin Blumenstingl <martin.blumenstingl@xxxxxxxxxxxxxx>
> > ---
> > Ulf, I consider this non-critical because as long as the meson-mx-sdhc
> > driver is not merged we only have one MMC driver for these platforms.
> > I don't know anybody to prefer SDIO wifi over SD card access, so this
> > can go into -next (in my option at least).
> >
>
> Alright, applied for next, thanks!
thank you for taking this patch!

I received a confirmation (off-list) saying that this patch works as it should.
Tobias was not Cc'ed on the original mail so he gave me to permission
(again, off-list - he's Cc'ed now) to add his:
Tested-by: Tobias Baumann <017623705678@xxxxxxxxxxx>


Martin