diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c index a34c1fab0246db..874490f7f5e7f6 100644 --- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c @@ -2947,37 +2947,59 @@ ufshcd_dev_cmd_completion(struct ufs_hba *hba, struct ufshcd_lrb *lrbp) static int ufshcd_wait_for_dev_cmd(struct ufs_hba *hba, struct ufshcd_lrb *lrbp, int max_timeout) { - int err = 0; - unsigned long time_left; + unsigned long time_left = msecs_to_jiffies(max_timeout); unsigned long flags; + bool pending; + int err; +retry: time_left = wait_for_completion_timeout(hba->dev_cmd.complete, - msecs_to_jiffies(max_timeout)); + time_left); - spin_lock_irqsave(hba->host->host_lock, flags); - hba->dev_cmd.complete = NULL; if (likely(time_left)) { + /* + * The completion handler called complete() and the caller of + * this function still owns the @lrbp tag so the code below does + * not trigger any race conditions. + */ + hba->dev_cmd.complete = NULL; err = ufshcd_get_tr_ocs(lrbp); if (!err) err = ufshcd_dev_cmd_completion(hba, lrbp); - } - spin_unlock_irqrestore(hba->host->host_lock, flags); - - if (!time_left) { + } else { err = -ETIMEDOUT; dev_dbg(hba->dev, "%s: dev_cmd request timedout, tag %d\n", __func__, lrbp->task_tag); - if (!ufshcd_clear_cmds(hba, 1U << lrbp->task_tag)) + if (ufshcd_clear_cmds(hba, 1U << lrbp->task_tag) == 0) { /* successfully cleared the command, retry if needed */ err = -EAGAIN; - /* - * in case of an error, after clearing the doorbell, - * we also need to clear the outstanding_request - * field in hba - */ - spin_lock_irqsave(&hba->outstanding_lock, flags); - __clear_bit(lrbp->task_tag, &hba->outstanding_reqs); - spin_unlock_irqrestore(&hba->outstanding_lock, flags); + /* + * Since clearing the command succeeded we also need to + * clear the task tag bit from the outstanding_reqs + * variable. + */ + spin_lock_irqsave(&hba->outstanding_lock, flags); + pending = test_bit(lrbp->task_tag, + &hba->outstanding_reqs); + if (pending) { + hba->dev_cmd.complete = NULL; + __clear_bit(lrbp->task_tag, + &hba->outstanding_reqs); + } + spin_unlock_irqrestore(&hba->outstanding_lock, flags); + + if (!pending) { + /* + * The completion handler ran while we tried to + * clear the command. + */ + time_left = 1; + goto retry; + } + } else { + dev_err(hba->dev, "%s: failed to clear tag %d\n", + __func__, lrbp->task_tag); + } } return err;