On 26 November 2015 at 03:51, Chaotian Jing <chaotian.jing@xxxxxxxxxxxx> wrote:
> there is a time window between __mmc_send_status() and time_afer(),
> on some eMMC chip, the timeout_ms is only 10ms, if this thread was
> scheduled out during this period, then, even card has already changes
> to transfer state by the result of CMD13, this part of code also treat
> it to timeout error.
> So, need calculate timeout first, then call __mmc_send_status(), if
> already timeout and card still in programing state, then treat it to
> the real timeout error.
>
> Signed-off-by: Chaotian Jing <chaotian.jing@xxxxxxxxxxxx>
> ---
> drivers/mmc/core/mmc_ops.c | 23 ++++++++++++++---------
> 1 file changed, 14 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/mmc/core/mmc_ops.c b/drivers/mmc/core/mmc_ops.c
> index 1f44426..0add634 100644
> --- a/drivers/mmc/core/mmc_ops.c
> +++ b/drivers/mmc/core/mmc_ops.c
> @@ -489,6 +489,7 @@ int __mmc_switch(struct mmc_card *card, u8 set, u8 index, u8 value,
> unsigned long timeout;
> u32 status = 0;
> bool use_r1b_resp = use_busy_signal;
> + bool expired = false;
No need to assign an initial value.
>
> mmc_retune_hold(host);
>
> @@ -544,10 +545,22 @@ int __mmc_switch(struct mmc_card *card, u8 set, u8 index, u8 value,
> /* Must check status to be sure of no errors. */
> timeout = jiffies + msecs_to_jiffies(timeout_ms);
> do {
> + /* Timeout if the device never leaves the program state.
Please start mutli-row comment with an empty line.
> + * must check it firstly to avoid problem caused by preempt.
Please rephrase this to:
Due to the possibility of being preempted after sending the status
command, check the expiration time first.
> + */
> + expired = time_after(jiffies, timeout);
I think we can move this inside the below "if (send_status) {"
.. but of course before sending the status command.
> +
> if (send_status) {
> err = __mmc_send_status(card, &status, ignore_crc);
> - if (err)
> + if (err) {
> goto out;
> + } else if (expired &&
You may use a new "if" statement instead of an "else if", due to the
above "goto out".
> + R1_CURRENT_STATE(status) == R1_STATE_PRG) {
> + pr_err("%s: Card stuck in programming state! %s\n",
> + mmc_hostname(host), __func__);
> + err = -ETIMEDOUT;
> + goto out;
> + }
> }
> if ((host->caps & MMC_CAP_WAIT_WHILE_BUSY) && use_r1b_resp)
> break;
> @@ -563,14 +576,6 @@ int __mmc_switch(struct mmc_card *card, u8 set, u8 index, u8 value,
> mmc_delay(timeout_ms);
> goto out;
> }
> -
> - /* Timeout if the device never leaves the program state. */
> - if (time_after(jiffies, timeout)) {
> - pr_err("%s: Card stuck in programming state! %s\n",
> - mmc_hostname(host), __func__);
> - err = -ETIMEDOUT;
> - goto out;
> - }
> } while (R1_CURRENT_STATE(status) == R1_STATE_PRG);
>
> err = mmc_switch_status_error(host, status);
> --
> 1.8.1.1.dirty
>
Kind regards
Uffe
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