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/[email protected]
Fixes: f5ef336fd2e4 ("scsi: ufs: core: Fix task management completion")
Reviewed-by: Bart Van Assche <[email protected]>
Signed-off-by: Adrian Hunter <[email protected]>
Signed-off-by: Martin K. Petersen <[email protected]>

0 files changed, 0 insertions, 0 deletions