scsi: ufs: core: Cancel RTC work during ufshcd_remove()

Currently, RTC work is only cancelled during __ufshcd_wl_suspend(). When
ufshcd is removed in ufshcd_remove(), RTC work is not cancelled. Due to
this, any further trigger of the RTC work after ufshcd_remove() would
result in a NULL pointer dereference as below:

Unable to handle kernel NULL pointer dereference at virtual address 00000000000002a4
Workqueue: events ufshcd_rtc_work
Call trace:
 _raw_spin_lock_irqsave+0x34/0x8c
 pm_runtime_get_if_active+0x24/0xb4
 ufshcd_rtc_work+0x124/0x19c
 process_scheduled_works+0x18c/0x2d8
 worker_thread+0x144/0x280
 kthread+0x11c/0x128
 ret_from_fork+0x10/0x20

Since RTC work accesses the ufshcd internal structures, it should be cancelled
when ufshcd is removed. So do that in ufshcd_remove(), as per the order in
ufshcd_init().

Cc: [email protected] # 6.8
Fixes: 6bf999e ("scsi: ufs: core: Add UFS RTC support")
Signed-off-by: Manivannan Sadhasivam <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: Peter Wang <[email protected]>
Reviewed-by: Bean Huo <[email protected]>
Reviewed-by: Bart Van Assche <[email protected]>
Signed-off-by: Martin K. Petersen <[email protected]>

Author: Mani-Sadhasivam

drivers/ufs/core/ufshcd.c

@@ -10189,6 +10189,7 @@ void ufshcd_remove(struct ufs_hba *hba)
 	ufs_hwmon_remove(hba);
 	ufs_bsg_remove(hba);
 	ufs_sysfs_remove_nodes(hba->dev);
+	cancel_delayed_work_sync(&hba->ufs_rtc_update_work);
 	blk_mq_destroy_queue(hba->tmf_queue);
 	blk_put_queue(hba->tmf_queue);
 	blk_mq_free_tag_set(&hba->tmf_tag_set);