[PATCH 09/14] scsi: mpt3sas: Remove in_interrupt().

Sebastian Andrzej Siewior
2020-11-26T13:30:38Z

From: "Ahmed S. Darwish" <a.darwish@linutronix.de>

_scsih_fw_event_cleanup_queue() waits for all outstanding firmware
events wokrqueue handlers to finish. If in_interrupt() is true, it
cancels itself and return early.

That in_interrupt() check is ill-defined and does not provide what the
name suggests: it does not cover all states in which it is safe to block
and call functions like cancel_work_sync().

That check is also not needed: _scsih_fw_event_cleanup_queue() is always
invoked from process context. Below is an analysis of its callers:

- scsih_remove(), bound to PCI ->remove(), process context

- scsih_shutdown(), bound to PCI ->shutdown(), process context

- mpt3sas_scsih_clear_outstanding_scsi_tm_commands(), called by
=> _base_clear_outstanding_commands(), called by
=>_base_fault_reset_work(), workqueue
=> mpt3sas_base_hard_reset_handler(), locks mutex

Remove the in_interrupt() check. Change _scsih_fw_event_cleanup_queue()
specification to a purely process-context function and mark it with
"Context: task, can sleep".

Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Sathya Prakash <sathya.prakash@broadcom.com>
Cc: Sreekanth Reddy <sreekanth.reddy@broadcom.com>
Cc: Suganath Prabu Subramani <suganath-prabu.subramani@broadcom.com>
Cc: <MPT-FusionLinux.pdl@broadcom.com>
---
drivers/scsi/mpt3sas/mpt3sas_scsih.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/mpt3sas/mpt3sas_scsih.c b/drivers/scsi/mpt3sas/mpt3sas_scsih.c
index f081adb85addc..d91f45abe6b86 100644
--- a/drivers/scsi/mpt3sas/mpt3sas_scsih.c
+++ b/drivers/scsi/mpt3sas/mpt3sas_scsih.c
@@ -3673,6 +3673,8 @@ static struct fw_event_work *dequeue_next_fw_event(struct MPT3SAS_ADAPTER *ioc)
*
* Walk the firmware event queue, either killing timers, or waiting
* for outstanding events to complete
+ *
+ * Context: task, can sleep
*/
static void
_scsih_fw_event_cleanup_queue(struct MPT3SAS_ADAPTER *ioc)
@@ -3680,7 +3682,7 @@ _scsih_fw_event_cleanup_queue(struct MPT3SAS_ADAPTER *ioc)
struct fw_event_work *fw_event;

if ((list_empty(&ioc->fw_event_list) && !ioc->current_event) ||
- !ioc->firmware_event_thread || in_interrupt())
+ !ioc->firmware_event_thread)
return;

ioc->fw_events_cleanup = 1;
--
2.29.2