Hi Chris
On Mon, 22 Apr 2013, Guennadi Liakhovetski wrote:
> When resuming, the tmio_mmc_host_resume() function is run when the
> controller might still be powered down. Issuing a reset command to it at
> that time has no effect. This patch postpones resetting the controller
> until the first powering-up .set_ios() call.
>
> Reported-by: Nguyen Viet Dung <nv-dung@xxxxxxxxxxx>
> Signed-off-by: Guennadi Liakhovetski <g.liakhovetski+renesas@xxxxxxxxx>
Any reason why this hasn't been applied yet? Please, push for 3.10.
Thanks
Guennadi
> ---
>
> There is some risk associated with this patch: it removes unconditional
> (attempt of) controller reset from the tmio_mmc_host_resume() function.
> AFAICS, this shouldn't have any negative effects. There _should_ always be
> a powering-up .set_ios() call after a resume. However, if anyone sees any
> (potential) problems with it, please, let me know.
>
> drivers/mmc/host/tmio_mmc.h | 1 +
> drivers/mmc/host/tmio_mmc_pio.c | 6 +++++-
> 2 files changed, 6 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/mmc/host/tmio_mmc.h b/drivers/mmc/host/tmio_mmc.h
> index d857f5c..759d8f4 100644
> --- a/drivers/mmc/host/tmio_mmc.h
> +++ b/drivers/mmc/host/tmio_mmc.h
> @@ -85,6 +85,7 @@ struct tmio_mmc_host {
> unsigned long last_req_ts;
> struct mutex ios_lock; /* protect set_ios() context */
> bool native_hotplug;
> + bool resuming;
> };
>
> int tmio_mmc_host_probe(struct tmio_mmc_host **host,
> diff --git a/drivers/mmc/host/tmio_mmc_pio.c b/drivers/mmc/host/tmio_mmc_pio.c
> index f508ecb..435cc4d 100644
> --- a/drivers/mmc/host/tmio_mmc_pio.c
> +++ b/drivers/mmc/host/tmio_mmc_pio.c
> @@ -862,6 +862,10 @@ static void tmio_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
> if (!host->power) {
> tmio_mmc_clk_update(mmc);
> pm_runtime_get_sync(dev);
> + if (host->resuming) {
> + tmio_mmc_reset(host);
> + host->resuming = false;
> + }
> }
> tmio_mmc_set_clock(host, ios->clock);
> if (!host->power) {
> @@ -1154,10 +1158,10 @@ int tmio_mmc_host_resume(struct device *dev)
> struct mmc_host *mmc = dev_get_drvdata(dev);
> struct tmio_mmc_host *host = mmc_priv(mmc);
>
> - tmio_mmc_reset(host);
> tmio_mmc_enable_dma(host, true);
>
> /* The MMC core will perform the complete set up */
> + host->resuming = true;
> return mmc_resume_host(mmc);
> }
> EXPORT_SYMBOL(tmio_mmc_host_resume);
> --
> 1.7.2.5
>
>
---
Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer
http://www.open-technology.de/
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