Prevent that both the interrupt handler and the reset handler try to
complete a request at the same time. This patch is the result of the
analysis of the following crash:
Unable to handle kernel NULL pointer dereference at virtual address 0000000000000120
CPU: 0 PID: 0 Comm: swapper/0 Tainted: G OE 5.10.107-android13-4-00051-g1e48e8970cca-ab8664745 #1
pc : ufshcd_release_scsi_cmd+0x30/0x46c
lr : __ufshcd_transfer_req_compl+0x4fc/0x9c0
Call trace:
ufshcd_release_scsi_cmd+0x30/0x46c
__ufshcd_transfer_req_compl+0x4fc/0x9c0
ufshcd_poll+0xf0/0x208
ufshcd_sl_intr+0xb8/0xf0
ufshcd_intr+0x168/0x2f4
__handle_irq_event_percpu+0xa0/0x30c
handle_irq_event+0x84/0x178
handle_fasteoi_irq+0x150/0x2e8
__handle_domain_irq+0x114/0x1e4
gic_handle_irq.31846+0x58/0x300
el1_irq+0xe4/0x1c0
cpuidle_enter_state+0x3ac/0x8c4
do_idle+0x2fc/0x55c
cpu_startup_entry+0x84/0x90
kernel_init+0x0/0x310
start_kernel+0x0/0x608
start_kernel+0x4ec/0x608
Signed-off-by: Bart Van Assche <bvanassche@xxxxxxx>
---
drivers/scsi/ufs/ufshcd.c | 20 +++++++++++++-------
1 file changed, 13 insertions(+), 7 deletions(-)
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 1fb3a8b9b03e..279691ff3562 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -6966,6 +6966,7 @@ int ufshcd_exec_raw_upiu_cmd(struct ufs_hba *hba,
*/
static int ufshcd_eh_device_reset_handler(struct scsi_cmnd *cmd)
{
+ unsigned long flags, completed_reqs = 0;
struct Scsi_Host *host;
struct ufs_hba *hba;
u32 pos;
@@ -6984,13 +6985,18 @@ static int ufshcd_eh_device_reset_handler(struct scsi_cmnd *cmd)
}
/* clear the commands that were pending for corresponding LUN */
- for_each_set_bit(pos, &hba->outstanding_reqs, hba->nutrs) {
- if (hba->lrb[pos].lun == lun) {
- err = ufshcd_clear_cmd(hba, pos);
- if (err)
- break;
- __ufshcd_transfer_req_compl(hba, 1U << pos);
- }
+ spin_lock_irqsave(&hba->outstanding_lock, flags);
+ for_each_set_bit(pos, &hba->outstanding_reqs, hba->nutrs)
+ if (hba->lrb[pos].lun == lun)
+ __set_bit(pos, &completed_reqs);
+ hba->outstanding_reqs &= ~completed_reqs;
+ spin_unlock_irqrestore(&hba->outstanding_lock, flags);
+
+ for_each_set_bit(pos, &completed_reqs, hba->nutrs) {
+ err = ufshcd_clear_cmd(hba, pos);
+ if (err)
+ break;
+ __ufshcd_transfer_req_compl(hba, 1U << pos);
}
out:
