Re: [<PATCH v1> 7/9] mmc: core: Skip frequency retries for SDCC slots

From: Greg KH
Date: Wed Dec 18 2019 - 03:34:53 EST


On Mon, Dec 16, 2019 at 06:50:40PM -0800, Bao D. Nguyen wrote:
> From: Sujith Reddy Thumma <sthumma@xxxxxxxxxxxxxx>
>
> Qualcomm SDCC controller supports minimum SD clock frequency
> which is required for card initialization. This information is
> exported through platform data for each SDCC controller. There is
> no need of retrying higher frequencies than the minimum supported
> by controller for Qualcomm chipsets which inturn add delay in
> detection process if there is no card during suspend/resume cycles.
> Hence, skip multiple frequency retries.
>
> Signed-off-by: Sujith Reddy Thumma <sthumma@xxxxxxxxxxxxxx>
> Signed-off-by: Subhash Jadavani <subhashj@xxxxxxxxxxxxxx>
> Signed-off-by: Xiaonian Wang <xiaonian@xxxxxxxxxxxxxx>
> Signed-off-by: Bao D. Nguyen <nguyenb@xxxxxxxxxxxxxx>
> ---
> drivers/mmc/core/core.c | 9 +--------
> 1 file changed, 1 insertion(+), 8 deletions(-)
>
> diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
> index 1e37f78..38b0cec 100644
> --- a/drivers/mmc/core/core.c
> +++ b/drivers/mmc/core/core.c
> @@ -2281,7 +2281,6 @@ void mmc_rescan(struct work_struct *work)
> {
> struct mmc_host *host =
> container_of(work, struct mmc_host, detect.work);
> - int i;
>
> if (host->rescan_disable)
> return;
> @@ -2332,13 +2331,7 @@ void mmc_rescan(struct work_struct *work)
> mmc_release_host(host);
> goto out;
> }
> -
> - for (i = 0; i < ARRAY_SIZE(freqs); i++) {
> - if (!mmc_rescan_try_freq(host, max(freqs[i], host->f_min)))
> - break;
> - if (freqs[i] <= host->f_min)
> - break;
> - }
> + mmc_rescan_try_freq(host, host->f_min);

What about for non-qualcomm controllers? Did this just break their
functionality?

thanks,

greg k-h