Re: [PATCH v2] ARM: dts: rockchip: temporarily remove emmc hs200 speed from rk3288-veyron-speedy.

[Paul Kocialkowski <contact-W9ppeneeCTY@public.gmane.org>]

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Hi,

Le mardi 18 octobre 2016 à 11:21 +0200, Heiko Stübner a écrit :
> Am Sonntag, 16. Oktober 2016, 21:49:43 schrieb Paul Kocialkowski:
> > 
> > Hi,
> > 
> > Le mardi 27 septembre 2016 à 13:53 -0700, Vagrant Cascadian a écrit :
> > > 
> > > This essentially mimics what was done with rk3288-veyron-minnie in
> > > commit 984926781122f034d5bc9962815d135b6c4a8e1d.
> > > 
> > > The eMMC of the speedy Chromebook also appears to need the same tuning
> > > workaround, as it frequently fails to recognize the eMMC without it.
> > 
> > I have a device where (without this patch) eMMC sometimes fails, with:
> > [    3.561010] dwmmc_rockchip ff0f0000.dwmmc: Successfully tuned phase to
> > 175 [    3.571742] mmc2: new HS200 MMC card at address 0001
> > [    3.571943] mmcblk2: mmc2:0001 HAG2e 14.7 GiB 
> > [    3.572026] mmcblk2boot0: mmc2:0001 HAG2e partition 1 4.00 MiB
> > [    3.572107] mmcblk2boot1: mmc2:0001 HAG2e partition 2 4.00 MiB
> > [    3.572181] mmcblk2rpmb: mmc2:0001 HAG2e partition 3 4.00 MiB
> > [    3.685647] mmcblk2: error -110 transferring data, sector 0, nr 8, cmd
> > response 0x900, card status 0x0
> > 
> > And sometimes works, with:
> > [    3.451058] dwmmc_rockchip ff0f0000.dwmmc: Successfully tuned phase to
> > 176 [    3.491093] mmc2: new HS200 MMC card at address 0001
> > [    3.491277] mmcblk2: mmc2:0001 HAG2e 14.7 GiB 
> > [    3.491345] mmcblk2boot0: mmc2:0001 HAG2e partition 1 4.00 MiB
> > [    3.491409] mmcblk2boot1: mmc2:0001 HAG2e partition 2 4.00 MiB
> > [    3.491474] mmcblk2rpmb: mmc2:0001 HAG2e partition 3 4.00 MiB
> > [    3.493548]  mmcblk2: p1 p2
> > 
> > However, with this change, it always fails, with:
> > [    3.322129] mmc_host mmc2: Bus speed (slot 0) = 50000000Hz (slot req
> > 52000000Hz, actual 50000000HZ div = 0) [    3.333174] mmc2: error -110
> > whilst initialising MMC card
> > 
> > I don't have so much time to investigate this issue, but it's clear that
> > this patch doesn't fix the issue (and actually worsens it) for my device.
> 
> thanks for the heads up.
> 
> As discussed on IRC we now have varying reports of the emmc working or not 
> working with and without that patch applied. So it's not really a bandaid fix 
> and I've thus dropped this patch again.

Thanks for dropping it! For the record, my eMMC shows up as:
mmcblk2: mmc2:0001 HAG2e 14.7 GiB

Maybe it could help to share what each tested device reports as eMMC model and
associate that with the current behavior, in spite of getting a clearer idea of
what issue affects what model.

> Still hoping someone will find the source of the problem somewhere :-)

I have started investigating the issue, but did not discover anything
significant yet. I hope I'll be able to figure it out!

Cheers!

-- 
Paul Kocialkowski, developer of free digital technology at the lower levels

Website: https://www.paulk.fr/
Coding blog: https://code.paulk.fr/
Git repositories: https://git.paulk.fr/ https://git.code.paulk.fr/

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