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SubjectRe: [RFC PATCH 2/2] mmc: core: sdio: claim host before power up or power off
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On 24 August 2015 at 12:15, Kishon Vijay Abraham I <kishon@ti.com> wrote:
> mmc_sdio_runtime_resume and mmc_sdio_runtime_suspend does power up and
> power off respectively but does so without claiming the host. Among other
> things mmc_claim_host inovkes pm_runtime_get_sync to enable the clocks.
> Invoke mmc_claim_host before mmc_power_up and mmc_power_off in
> mmc_sdio_runtime_resume and mmc_sdio_runtime_suspend respectively.
>
> This is required since certain platforms (like TI SoCs) access
> the controller registers during power up.

I realize the issue. Actually I have been working on similar patch
which take a bit wider approach. That's because there are more cases
where the host needs to be claimed, when it isn't.

I just posted a patch, please have a look and see if it makes sense to
you, you are on cc.
"[PATCH] mmc: core: Keep host claimed while invoking mmc_power_off|up()"

Kind regards
Uffe

>
> Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
> ---
> drivers/mmc/core/sdio.c | 10 +++++++++-
> 1 file changed, 9 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/mmc/core/sdio.c b/drivers/mmc/core/sdio.c
> index 0cbbfb8..40795b2 100644
> --- a/drivers/mmc/core/sdio.c
> +++ b/drivers/mmc/core/sdio.c
> @@ -1023,16 +1023,24 @@ static int mmc_sdio_power_restore(struct mmc_host *host)
>
> static int mmc_sdio_runtime_suspend(struct mmc_host *host)
> {
> + mmc_claim_host(host);
> /* No references to the card, cut the power to it. */
> mmc_power_off(host);
> + mmc_release_host(host);
> return 0;
> }
>
> static int mmc_sdio_runtime_resume(struct mmc_host *host)
> {
> + int ret;
> +
> + mmc_claim_host(host);
> /* Restore power and re-initialize. */
> mmc_power_up(host, host->card->ocr);
> - return mmc_sdio_power_restore(host);
> + ret = _mmc_sdio_power_restore(host);
> + mmc_release_host(host);
> +
> + return ret;
> }
>
> static int mmc_sdio_reset(struct mmc_host *host)
> --
> 1.7.9.5
>


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