On 20/10/16 11:19, Ulf Hansson wrote:
> When polling for busy after sending a MMC_SWITCH command, both the optional
> ->card_busy() callback and CMD13 are being used in conjunction.
>
> This doesn't make sense. Instead it's more reasonable to rely solely on the
> ->card_busy() callback when it exists. Let's change that and instead use
> the CMD13 as a fall-back. In this way we avoid sending CMD13, unless it's
> really needed.
>
> Within this context, let's also take the opportunity to make some
> additional clean-ups and clarifications to the related code.
>
> Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
> ---
> drivers/mmc/core/mmc_ops.c | 30 ++++++++++++++----------------
> 1 file changed, 14 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/mmc/core/mmc_ops.c b/drivers/mmc/core/mmc_ops.c
> index a84a880..481bbdb 100644
> --- a/drivers/mmc/core/mmc_ops.c
> +++ b/drivers/mmc/core/mmc_ops.c
> @@ -495,34 +495,32 @@ static int mmc_poll_for_busy(struct mmc_card *card, unsigned int timeout_ms,
> timeout = jiffies + msecs_to_jiffies(timeout_ms) + 1;
> do {
> /*
> - * Due to the possibility of being preempted after
> - * sending the status command, check the expiration
> - * time first.
> + * Due to the possibility of being preempted while polling,
> + * check the expiration time first.
> */
> expired = time_after(jiffies, timeout);
> - if (send_status) {
> +
> + if (host->ops->card_busy) {
> + busy = host->ops->card_busy(host);
I didn't really have time to look at these patches, sorry :-(. But this
loop looks like it could use a cond_resched()
> + } else {
> err = __mmc_send_status(card, &status, ignore_crc);
> if (err)
> return err;
> - }
> - if (host->ops->card_busy) {
> - if (!host->ops->card_busy(host))
> - break;
> - busy = true;
> + busy = R1_CURRENT_STATE(status) == R1_STATE_PRG;
> }
>
> - /* Timeout if the device never leaves the program state. */
> - if (expired &&
> - (R1_CURRENT_STATE(status) == R1_STATE_PRG || busy)) {
> - pr_err("%s: Card stuck in programming state! %s\n",
> + /* Timeout if the device still remains busy. */
> + if (expired && busy) {
> + pr_err("%s: Card stuck being busy! %s\n",
> mmc_hostname(host), __func__);
> return -ETIMEDOUT;
> }
> - } while (R1_CURRENT_STATE(status) == R1_STATE_PRG || busy);
> + } while (busy);
>
> - err = mmc_switch_status_error(host, status);
> + if (host->ops->card_busy && send_status)
> + return mmc_switch_status(card);
>
> - return err;
> + return mmc_switch_status_error(host, status);
> }
>
> /**
>
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