From: Bart Van Assche bvanassche@acm.org
[ Upstream commit ee8c88cab4afbd5ee10a127d6cbecd6b200185a5 ]
Fix the following issues in ufshcd_poll():
- If polling succeeds, return a positive value.
- Do not complete polling requests from interrupt context because the block layer expects these requests to be completed from thread context. From block/bio.c:
If REQ_ALLOC_CACHE is set, the final put of the bio MUST be done from process context, not hard/soft IRQ.
Fixes: eaab9b573054 ("scsi: ufs: Implement polling support") Signed-off-by: Bart Van Assche bvanassche@acm.org Link: https://lore.kernel.org/r/20221118233717.441298-1-bvanassche@acm.org Reviewed-by: Adrian Hunter adrian.hunter@intel.com Signed-off-by: Martin K. Petersen martin.petersen@oracle.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/ufs/core/ufshcd.c | 28 ++++++++++++++++++++++++++-- 1 file changed, 26 insertions(+), 2 deletions(-)
diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c index b1f59a5fe632..5432be4cd0ed 100644 --- a/drivers/ufs/core/ufshcd.c +++ b/drivers/ufs/core/ufshcd.c @@ -5382,6 +5382,26 @@ static void __ufshcd_transfer_req_compl(struct ufs_hba *hba, } }
+/* Any value that is not an existing queue number is fine for this constant. */ +enum { + UFSHCD_POLL_FROM_INTERRUPT_CONTEXT = -1 +}; + +static void ufshcd_clear_polled(struct ufs_hba *hba, + unsigned long *completed_reqs) +{ + int tag; + + for_each_set_bit(tag, completed_reqs, hba->nutrs) { + struct scsi_cmnd *cmd = hba->lrb[tag].cmd; + + if (!cmd) + continue; + if (scsi_cmd_to_rq(cmd)->cmd_flags & REQ_POLLED) + __clear_bit(tag, completed_reqs); + } +} + /* * Returns > 0 if one or more commands have been completed or 0 if no * requests have been completed. @@ -5398,13 +5418,17 @@ static int ufshcd_poll(struct Scsi_Host *shost, unsigned int queue_num) WARN_ONCE(completed_reqs & ~hba->outstanding_reqs, "completed: %#lx; outstanding: %#lx\n", completed_reqs, hba->outstanding_reqs); + if (queue_num == UFSHCD_POLL_FROM_INTERRUPT_CONTEXT) { + /* Do not complete polled requests from interrupt context. */ + ufshcd_clear_polled(hba, &completed_reqs); + } hba->outstanding_reqs &= ~completed_reqs; spin_unlock_irqrestore(&hba->outstanding_lock, flags);
if (completed_reqs) __ufshcd_transfer_req_compl(hba, completed_reqs);
- return completed_reqs; + return completed_reqs != 0; }
/** @@ -5435,7 +5459,7 @@ static irqreturn_t ufshcd_transfer_req_compl(struct ufs_hba *hba) * Ignore the ufshcd_poll() return value and return IRQ_HANDLED since we * do not want polling to trigger spurious interrupt complaints. */ - ufshcd_poll(hba->host, 0); + ufshcd_poll(hba->host, UFSHCD_POLL_FROM_INTERRUPT_CONTEXT);
return IRQ_HANDLED; }