Hi Wolfram,
On Fri, Apr 1, 2016 at 5:44 PM, Wolfram Sang <wsa@xxxxxxxxxxxxx> wrote:
> From: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>
>
> Based on work by Shinobu Uehara and Ben Dooks. This adds the voltage
> switch operation needed for all UHS-I modes, but not the tuning needed
> for SDR-104 which will come later.
>
> Signed-off-by: Ben Hutchings <ben.hutchings@xxxxxxxxxxxxxxx>
> Signed-off-by: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>
This patch causes a regression on r8a73a4/ape6evm, where the system feels
sluggish, and the load average is always ca. 1.
According to "top", "kworker/0:1" is consuming up to 80% of CPU time.
"echo t > /proc/sysrq-trigger" tells me:
kworker/0:1 R running 0 57 2 0x00000000
Workqueue: events_freezable mmc_rescan
[<c0465e3c>] (__schedule) from [<c04662c4>]
(preempt_schedule_common+0x1c/0x2c)
[<c04662c4>] (preempt_schedule_common) from [<c0466430>]
(_cond_resched+0x34/0x44)
[<c0466430>] (_cond_resched) from [<c02f9d04>]
(__mmc_start_request+0x6c/0x204)
[<c02f9d04>] (__mmc_start_request) from [<c02f9fa0>]
(mmc_start_request+0x104/0x118)
[<c02f9fa0>] (mmc_start_request) from [<c02fa4b0>]
(mmc_wait_for_req+0x3c/0x14c)
[<c02fa4b0>] (mmc_wait_for_req) from [<c02fa624>]
(mmc_wait_for_cmd+0x64/0x74)
[<c02fa624>] (mmc_wait_for_cmd) from [<c03041dc>]
(mmc_io_rw_direct_host+0xbc/0x124)
[<c03041dc>] (mmc_io_rw_direct_host) from [<c0304608>]
(sdio_reset+0x58/0x60)
[<c0304608>] (sdio_reset) from [<c02fc4e8>] (mmc_rescan+0x244/0x338)
[<c02fc4e8>] (mmc_rescan) from [<c00469a8>] (process_one_work+0x324/0x67c)
[<c00469a8>] (process_one_work) from [<c0046fdc>]
(worker_thread+0x2ac/0x3d4)
[<c0046fdc>] (worker_thread) from [<c004caf4>] (kthread+0xd8/0xec)
[<c004caf4>] (kthread) from [<c000fc10>] (ret_from_fork+0x14/0x24)
I've bisected this to
commit 452e5eef6d311e52f657b34d999758107ec3dd4a
Author: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>
Date: Fri Apr 1 17:44:33 2016 +0200
mmc: tmio: Add UHS-I mode support
The problem goes away by:
1. Commenting-out the assignment to .card_busy
2. OR disabling the second SDHI channel, e.g.
echo ee120000.sd > /sys/bus/platform/drivers/sh_mobile_sdhi/unbind
The first SDHI channel (ee100000.sd) doesn't seem to be affected
by the problem.
I've added some debug code to dev_warn_ratelimited() the status value.
This shows the SDHI channel keeps on reporting busy:
# dmesg | grep -E "(tmio|sdhi)" | uniq -c
1 iommu: Adding device regulator-sdhi0 to group 0
1 iommu: Removing device regulator-sdhi0 from group 0
1 sh_mobile_sdhi ee100000.sd: could not find pctldev for node
/pfc@e6050000/sd0, deferring probe
1 sh_mobile_sdhi ee120000.sd: could not find pctldev for node
/pfc@e6050000/sd1, deferring probe
1 sh_mobile_sdhi ee100000.sd: adding to PM domain a3sp
1 _host->start_signal_voltage_switch =
sh_mobile_sdhi_start_signal_voltage_switch
1 sh_mobile_sdhi ee100000.sd: mmc0 base at 0xee100000 max clock
rate 88 MHz
1 sh_mobile_sdhi ee120000.sd: adding to PM domain a3sp
1 _host->start_signal_voltage_switch =
sh_mobile_sdhi_start_signal_voltage_switch
1 sh_mobile_sdhi ee100000.sd: CTL_STATUS2 = 0x20800600
1 sh_mobile_sdhi ee100000.sd: CTL_STATUS2 = 0x20800400
1 sh_mobile_sdhi ee120000.sd: mmc1 base at 0xee120000 max clock
rate 12 MHz
8 sh_mobile_sdhi ee120000.sd: CTL_STATUS2 = 0x20000600
1 tmio_mmc_card_busy: 3509 callbacks suppressed
10 sh_mobile_sdhi ee120000.sd: CTL_STATUS2 = 0x20000400
1 tmio_mmc_card_busy: 2653 callbacks suppressed
10 sh_mobile_sdhi ee120000.sd: CTL_STATUS2 = 0x20000400
1 tmio_mmc_card_busy: 2028 callbacks suppressed
10 sh_mobile_sdhi ee120000.sd: CTL_STATUS2 = 0x20000400
1 tmio_mmc_card_busy: 2888 callbacks suppressed
10 sh_mobile_sdhi ee120000.sd: CTL_STATUS2 = 0x20000400
Note that the reported values are the ones for a current tree.
On commit 452e5eef6d311e52, the values are 0x31d2080, 0x3002080,
0x31d2000, and 0x3182000.
As you can see ee100000.sd behaves normal.
> ---
> drivers/mmc/host/tmio_mmc.h | 2 ++
> drivers/mmc/host/tmio_mmc_pio.c | 12 +++++++++++-
> include/linux/mmc/tmio.h | 2 ++
> 3 files changed, 15 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/mmc/host/tmio_mmc.h b/drivers/mmc/host/tmio_mmc.h
> index b44b5890290622..b1819c74965b47 100644
> --- a/drivers/mmc/host/tmio_mmc.h
> +++ b/drivers/mmc/host/tmio_mmc.h
> @@ -101,6 +101,8 @@ struct tmio_mmc_host {
> void (*clk_disable)(struct tmio_mmc_host *host);
> int (*multi_io_quirk)(struct mmc_card *card,
> unsigned int direction, int blk_size);
> + int (*start_signal_voltage_switch)(struct mmc_host *mmc,
> + struct mmc_ios *ios);
> };
>
> struct tmio_mmc_host *tmio_mmc_host_alloc(struct platform_device *pdev);
> diff --git a/drivers/mmc/host/tmio_mmc_pio.c b/drivers/mmc/host/tmio_mmc_pio.c
> index ae81b34f17a5a5..53e5ba5a21914c 100644
> --- a/drivers/mmc/host/tmio_mmc_pio.c
> +++ b/drivers/mmc/host/tmio_mmc_pio.c
> @@ -1012,12 +1012,20 @@ static int tmio_multi_io_quirk(struct mmc_card *card,
> return blk_size;
> }
>
> -static const struct mmc_host_ops tmio_mmc_ops = {
> +static int tmio_mmc_card_busy(struct mmc_host *mmc)
> +{
> + struct tmio_mmc_host *host = mmc_priv(mmc);
> +
> + return !(sd_ctrl_read32(host, CTL_STATUS2) & TMIO_STATUS2_DAT0);
> +}
> +
> +static struct mmc_host_ops tmio_mmc_ops = {
> .request = tmio_mmc_request,
> .set_ios = tmio_mmc_set_ios,
> .get_ro = tmio_mmc_get_ro,
> .get_cd = mmc_gpio_get_cd,
> .enable_sdio_irq = tmio_mmc_enable_sdio_irq,
> + .card_busy = tmio_mmc_card_busy,
> .multi_io_quirk = tmio_multi_io_quirk,
> };
>
> @@ -1116,7 +1124,9 @@ int tmio_mmc_host_probe(struct tmio_mmc_host *_host,
> goto host_free;
> }
>
> + tmio_mmc_ops.start_signal_voltage_switch = _host->start_signal_voltage_switch;
> mmc->ops = &tmio_mmc_ops;
> +
> mmc->caps |= MMC_CAP_4_BIT_DATA | pdata->capabilities;
> mmc->caps2 |= pdata->capabilities2;
> mmc->max_segs = 32;
> diff --git a/include/linux/mmc/tmio.h b/include/linux/mmc/tmio.h
> index 5f5cd80e976500..b2f28e99503383 100644
> --- a/include/linux/mmc/tmio.h
> +++ b/include/linux/mmc/tmio.h
> @@ -63,6 +63,8 @@
> #define TMIO_STAT_CMD_BUSY 0x40000000
> #define TMIO_STAT_ILL_ACCESS 0x80000000
>
> +#define TMIO_STATUS2_DAT0 BIT(7)
> +
> #define CLK_CTL_DIV_MASK 0xff
> #define CLK_CTL_SCLKEN BIT(8)
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
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