There is some more information regarding SD card support in https://github.com/96boards/bugs/issues/4. I've documented some info I received from engineering.

On Tue, Mar 10, 2015 at 6:54 AM, Koen Kooi koen.kooi@linaro.org wrote:

Op 10 mrt. 2015, om 11:41 heeft Steve Taylor steve.taylor@linaro.org het volgende geschreven:

...

Hi all,

From: https://www.96boards.org/forums/topic/problem-with-microsd-card/#post-6695

There seems to be a conflict between the microSD card and other USB peripherals (in my particular case, a USB-ethernet dongle). When the USB-ethernet is connected, the kernel reports the following errors

[ 2571.527346] dwmmc_k3 f723e000.dwmmc1: failed to set rate 0Hz [ 2571.547337] dwmmc_k3 f723e000.dwmmc1: failed to set rate 400000Hz [ 2571.570917] dwmmc_k3 f723e000.dwmmc1: failed to set rate 400000Hz [ 2571.573227] dwmmc_k3 f723e000.dwmmc1: failed to set rate 400000Hz [ 2571.588534] dwmmc_k3 f723e000.dwmmc1: failed to set rate 400000Hz [ 2571.590143] dwmmc_k3 f723e000.dwmmc1: failed to set rate 0Hz

And the microSD card is not discovered. Absent the USB-ethernet dongle, it works ok.

I disagree, without the ethernet dongle I don't have reliable networking :)

...

Has anyone encountered this error,

Yes

...

and has any suggestion how it could be fixed?

It can be fixed with a proper clock driver by the looks of it. With 4.0.0-rc3 you'll also get tons of these:

Mar 10 10:49:47 hikey kernel: INFO: task kworker/u16:1:49 blocked for more than 120 seconds. Mar 10 10:49:47 hikey kernel: Tainted: G W 4.0.0-rc3 #11 Mar 10 10:49:47 hikey kernel: "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. Mar 10 10:49:47 hikey kernel: kworker/u16:1 D ffffffc000086c00 0 49 2 0x00000000 Mar 10 10:49:47 hikey kernel: Workqueue: kmmcd mmc_rescan Mar 10 10:49:47 hikey kernel: Call trace: Mar 10 10:49:48 hikey kernel: [<ffffffc000086c00>] __switch_to+0x5c/0x68 Mar 10 10:49:48 hikey kernel: [<ffffffc0007e48b8>] __schedule+0x29c/0x6ac Mar 10 10:49:48 hikey kernel: [<ffffffc0007e4cf8>] schedule+0x30/0x8c Mar 10 10:49:48 hikey kernel: [<ffffffc0007e74d8>] schedule_timeout+0x140/0x1dc Mar 10 10:49:48 hikey kernel: [<ffffffc0007e5774>] wait_for_common+0xac/0x15c Mar 10 10:49:48 hikey kernel: [<ffffffc0007e5834>] wait_for_completion+0x10/0x1c Mar 10 10:49:48 hikey kernel: [<ffffffc0006088d0>] mmc_wait_for_req_done+0x40/0x140 Mar 10 10:49:48 hikey kernel: [<ffffffc000608a58>] mmc_wait_for_cmd+0x58/0x88 Mar 10 10:49:48 hikey kernel: [<ffffffc000613924>] mmc_io_rw_direct_host+0x78/0x138 Mar 10 10:49:48 hikey kernel: [<ffffffc000613e84>] sdio_reset+0x24/0x70 Mar 10 10:49:48 hikey kernel: [<ffffffc00060b5a0>] mmc_rescan+0x260/0x2f0 Mar 10 10:49:48 hikey kernel: [<ffffffc0000c2860>] process_one_work+0x140/0x348 Mar 10 10:49:48 hikey kernel: [<ffffffc0000c3318>] worker_thread+0x140/0x48c Mar 10 10:49:48 hikey kernel: [<ffffffc0000c7afc>] kthread+0xd8/0xf0

I did notice that the uSD card gets detected more often with 3.18 when using UEFI instead of the evil vendor loader. Still not 100% reliable, but a lot better. With UEFI+4.0.0-rc3 the kernel crashes with a uSD inserted.

-- Koen Kooi Builds and Baselines | Release Manager Linaro.org | Open source software for ARM SoCs

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Dev mailing list Dev@lists.96boards.org https://lists.96boards.org/mailman/listinfo/dev

Hi Fathi / all,

...

[ 2571.527346] dwmmc_k3 f723e000.dwmmc1: failed to set rate 0Hz [ 2571.547337] dwmmc_k3 f723e000.dwmmc1: failed to set rate 400000Hz [ 2571.570917] dwmmc_k3 f723e000.dwmmc1: failed to set rate 400000Hz [ 2571.573227] dwmmc_k3 f723e000.dwmmc1: failed to set rate 400000Hz [ 2571.588534] dwmmc_k3 f723e000.dwmmc1: failed to set rate 400000Hz [ 2571.590143] dwmmc_k3 f723e000.dwmmc1: failed to set rate 0Hz

And the microSD card is not discovered. Absent the USB-ethernet dongle, it works ok. Has anyone encountered this error, and has any suggestion how it could

be fixed?

known issue. Bintian is supposed to look that.

Are we tracking these issues somewhere along with who's working on them?

I don't want to go working on things other people are already in the process of fixing.

regards,

Peter.

Is this logged as a bug?

On Tue, Mar 10, 2015 at 6:56 AM, Fathi Boudra fathi.boudra@linaro.org wrote:

On 10 March 2015 at 12:41, Steve Taylor steve.taylor@linaro.org wrote:

...

Hi all,

From:

https://www.96boards.org/forums/topic/problem-with-microsd-card/#post-6695

...

There seems to be a conflict between the microSD card and other USB peripherals (in my particular case, a USB-ethernet dongle). When the USB-ethernet is connected, the kernel reports the following errors

[ 2571.527346] dwmmc_k3 f723e000.dwmmc1: failed to set rate 0Hz [ 2571.547337] dwmmc_k3 f723e000.dwmmc1: failed to set rate 400000Hz [ 2571.570917] dwmmc_k3 f723e000.dwmmc1: failed to set rate 400000Hz [ 2571.573227] dwmmc_k3 f723e000.dwmmc1: failed to set rate 400000Hz [ 2571.588534] dwmmc_k3 f723e000.dwmmc1: failed to set rate 400000Hz [ 2571.590143] dwmmc_k3 f723e000.dwmmc1: failed to set rate 0Hz

And the microSD card is not discovered. Absent the USB-ethernet dongle, it works ok. Has anyone encountered this error, and has any suggestion how it could

be fixed?

known issue. Bintian is supposed to look that.

...

Thanks

Steve

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