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authorAdrian Hunter <adrian.hunter@intel.com>2021-11-08 08:48:15 +0200
committerMartin K. Petersen <martin.petersen@oracle.com>2021-11-16 19:42:32 -0500
commit5cb37a26355d79ab290220677b1b57d28e99a895 (patch)
tree7b722eff8ccd14e96733c06e36404d012f99568e /drivers/scsi
parent886fe2915cce6658b0fc19e64b82879325de61ea (diff)
scsi: ufs: core: Fix another task management completion race
hba->outstanding_tasks, which is read under host_lock spinlock, tells the interrupt handler what task management tags are in use by the driver. The doorbell register bits indicate which tags are in use by the hardware. A doorbell bit that is 0 is because the bit has yet to be set by the driver, or because the task is complete. It is only possible to disambiguate the 2 cases, if reading/writing the doorbell register is synchronized with reading/writing hba->outstanding_tasks. For that reason, reading REG_UTP_TASK_REQ_DOOR_BELL must be done under spinlock. Link: https://lore.kernel.org/r/20211108064815.569494-3-adrian.hunter@intel.com Fixes: f5ef336fd2e4 ("scsi: ufs: core: Fix task management completion") Reviewed-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Diffstat (limited to 'drivers/scsi')
-rw-r--r--drivers/scsi/ufs/ufshcd.c3
1 files changed, 1 insertions, 2 deletions
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index c18aa9a43f0a..13c09dbd99b9 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -6453,9 +6453,8 @@ static irqreturn_t ufshcd_tmc_handler(struct ufs_hba *hba)
irqreturn_t ret = IRQ_NONE;
int tag;
- pending = ufshcd_readl(hba, REG_UTP_TASK_REQ_DOOR_BELL);
-
spin_lock_irqsave(hba->host->host_lock, flags);
+ pending = ufshcd_readl(hba, REG_UTP_TASK_REQ_DOOR_BELL);
issued = hba->outstanding_tasks & ~pending;
for_each_set_bit(tag, &issued, hba->nutmrs) {
struct request *req = hba->tmf_rqs[tag];