mirrors/linux-stable
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git synced 2024-09-29 22:02:02 +00:00
Code Issues Releases Wiki Activity

scsi: ufs: core: Fix the polling implementation

Browse source 
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: eaab9b5730 ("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>
This commit is contained in:
Bart Van Assche 2022-11-18 15:37:03 -08:00 committed by Martin K. Petersen
parent 4d450cf2b0
commit ee8c88cab4
1 changed files with 26 additions and 2 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

28
drivers/ufs/core/ufshcd.c
View file

@ -5344,6 +5344,26 @@ 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.
@ -5360,13 +5380,17 @@ 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;
}
/**
@ -5397,7 +5421,7 @@ 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;
}