From: Adrian Hunter adrian.hunter@intel.com
[ Upstream commit 5cb37a26355d79ab290220677b1b57d28e99a895 ]
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 Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/scsi/ufs/ufshcd.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c index 3d0da8b3fed8a..55f2e4d6f10b7 100644 --- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c @@ -6382,9 +6382,8 @@ 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];