msm: camera: isp: Use spin lock bh to avoid thread preemption

Use spin_lock_bh utility to avoid the preemtpion of recovery thread
in ISP context. This can come in rare conditions when IRQ is received
on same CPU which is handling the thread.
Such cases will result in deadlock conditions.

CRs-Fixed: 3208733
Change-Id: I25fde15b484fd72fa779aed393ef94d4fbb183b6
Signed-off-by: Gaurav Jindal <[email protected]>

drivers/cam_isp/cam_isp_context.c

@@ -7287,9 +7287,9 @@ static int __cam_isp_ctx_reset_and_recover(
 	struct cam_ctx_request               *req;
 	struct cam_isp_ctx_req               *req_isp;
 
-	spin_lock(&ctx->lock);
+	spin_lock_bh(&ctx->lock);
 	if (ctx_isp->active_req_cnt) {
-		spin_unlock(&ctx->lock);
+		spin_unlock_bh(&ctx->lock);
 		CAM_WARN(CAM_ISP,
 			"Active list not empty: %u in ctx: %u on link: 0x%x, retry recovery for req: %lld after buf_done",
 			ctx_isp->active_req_cnt, ctx->ctx_id,
@@ -7298,7 +7298,7 @@ static int __cam_isp_ctx_reset_and_recover(
 	}
 
 	if (ctx->state != CAM_CTX_ACTIVATED) {
-		spin_unlock(&ctx->lock);
+		spin_unlock_bh(&ctx->lock);
 		CAM_ERR(CAM_ISP,
 			"In wrong state %d, for recovery ctx: %u in link: 0x%x recovery req: %lld",
 			ctx->state, ctx->ctx_id,
@@ -7309,16 +7309,16 @@ static int __cam_isp_ctx_reset_and_recover(
 
 	if (list_empty(&ctx->pending_req_list)) {
 		/* Cannot start with no request */
-		spin_unlock(&ctx->lock);
+		spin_unlock_bh(&ctx->lock);
 		CAM_ERR(CAM_ISP,
 			"Failed to reset and recover last_applied_req: %llu in ctx: %u on link: 0x%x",
 			ctx_isp->last_applied_req_id, ctx->ctx_id, ctx->link_hdl);
 		rc = -EFAULT;
 		goto end;
 	}
-	spin_unlock(&ctx->lock);
 
 	if (!ctx_isp->hw_ctx) {
+		spin_unlock_bh(&ctx->lock);
 		CAM_ERR(CAM_ISP,
 			"Invalid hw context pointer ctx: %u on link: 0x%x",
 			ctx->ctx_id, ctx->link_hdl);
@@ -7331,6 +7331,8 @@ static int __cam_isp_ctx_reset_and_recover(
 
 	req = list_first_entry(&ctx->pending_req_list,
 		struct cam_ctx_request, list);
+	spin_unlock_bh(&ctx->lock);
+
 	req_isp = (struct cam_isp_ctx_req *) req->req_priv;
 
 	CAM_INFO(CAM_ISP,