Re: [PATCH v4 0/3] about data busy

Javier Martinez Canillas
2015-02-15T11:41:59Z

Hello Addy,

On Sat, Feb 14, 2015 at 7:17 AM, Addy Ke <addy.ke@rock-chips.com> wrote:
> patch 1: This patch can fix bug that controller is still data busy after
> reset all blocks. After this patch, I still get data busy in
> set_ios().
>
> patch 2: This patch fix bug 'Timeout sending command'. After patch1 and
> patch2, there is no mmc errors after:
> cd /sys/bus/platform/drivers/dwmmc_rockchip
> for i in $(seq 1 10000); do
> echo "========================" $i
> echo ff0c0000.dwmmc > unbind
> sleep .5
> echo ff0c0000.dwmmc > bind
> sleep 2
> done
>
> patch3: This patch fix bug that there is data busy before sdio send CMD53.
> But This patch is necessary for sd and mmc too.
>

I faced the same 'Timeout sending command' error when trying to enable
support for the SDIO wifi chip attached to mmc@12210000 (mmc1) on an
Exynos5420 Peach Pit Chromebook. On booting the kernel log shows:

mmc_host mmc1: Timeout sending command (cmd 0x202000 arg 0x0 status 0x80202000)

0x202000 == SDMMC_CMD_UPD_CLK | SDMMC_CMD_PRV_DAT_WAIT so your patch
#2 dw_mci_setup_bus() avoids the mmc comand to time out. However, it
has a side effect since with your series the uSD that in mmc@12220000
(mmc2) fails to be detected and the kernel log shows:

[ 5.466432] Waiting for root device /dev/mmcblk1p4...
[ 240.169436] INFO: task kworker/u16:1:50 blocked for more than 120 seconds.
[ 240.174844] Not tainted
3.19.0-next-20150211-00006-g045d4aba96ce-dirty #476
[ 240.182302] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs"
disables this message.
[ 240.190109] kworker/u16:1 D c04c2710 0 50 2 0x00000000
[ 240.196446] Workqueue: kmmcd mmc_rescan
[ 240.200249] [<c04c2710>] (__schedule) from [<c04c2ac0>] (schedule+0x34/0x98)
[ 240.207290] [<c04c2ac0>] (schedule) from [<c04c6568>]
(schedule_timeout+0x120/0x16c)
[ 240.215009] [<c04c6568>] (schedule_timeout) from [<c04c3584>]
(wait_for_common+0xb0/0x154)
[ 240.223251] [<c04c3584>] (wait_for_common) from [<c038a5ac>]
(mmc_wait_for_req+0xa0/0x140)
[ 240.231492] [<c038a5ac>] (mmc_wait_for_req) from [<c038a6d4>]
(mmc_wait_for_cmd+0x88/0xa8)
[ 240.239735] [<c038a6d4>] (mmc_wait_for_cmd) from [<c03905b0>]
(mmc_go_idle+0x78/0xf8)
[ 240.247540] [<c03905b0>] (mmc_go_idle) from [<c038c578>]
(mmc_rescan+0x254/0x300)
[ 240.255003] [<c038c578>] (mmc_rescan) from [<c00346e8>]
(process_one_work+0x120/0x324)
[ 240.262897] [<c00346e8>] (process_one_work) from [<c0034a58>]
(worker_thread+0x138/0x464)
[ 240.271048] [<c0034a58>] (worker_thread) from [<c0039070>]
(kthread+0xd8/0xf4)
[ 240.278254] [<c0039070>] (kthread) from [<c000e680>]
(ret_from_fork+0x14/0x34)

By enabling debug I see that the card is detected in dw_mci_get_cd() though.

Alim suggested [0] that dw_mci_wait_busy() should be called in
mci_send_cmd() instead dw_mci_setup_bus() because the controller hangs
when when sending update clock cmd in different cases.

I modified [1] your patch #2 to do what Alim suggested and only with
that patch on top of linux-next I have neither the the "Timeout
sending command" error nor the uSD not getting detected errors. Linux
mounts the rootfs from the uSD and the wifi SDIO device is enumerated
and listed in /sys/bus/sdio/devices/

Does that also solve your issue?

Best regards,
Javier

[0]: https://lkml.org/lkml/2015/2/10/353
[1]: http://paste.debian.net/plain/148794