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

["Heiko Stübner" <heiko-4mtYJXux2i+zQB+pC5nmwQ@public.gmane.org>]

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.

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


Heiko
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