drm/xe/lrc: Fix uninitialized new_ts when capturing context timestamp

Getting engine specific CTX TIMESTAMP register can fail. In that case,
if the context is active, new_ts is uninitialized. Fix that case by
initializing new_ts to the last value that was sampled in SW -
lrc->ctx_timestamp.

Flagged by static analysis.

v2: Fix new_ts initialization (Ashutosh)

Fixes: bb63e72 ("drm/xe: Avoid toggling schedule state to check LRC timestamp in TDR")
Signed-off-by: Umesh Nerlige Ramappa <[email protected]>
Reviewed-by: Ashutosh Dixit <[email protected]>
Link: https://patch.msgid.link/[email protected]
(cherry picked from commit 466e75d)
Signed-off-by: Thomas Hellström <[email protected]>

Author: unerlige

drivers/gpu/drm/xe/xe_lrc.c

@@ -2413,14 +2413,14 @@ static int get_ctx_timestamp(struct xe_lrc *lrc, u32 engine_id, u64 *reg_ctx_ts)
  * @lrc: Pointer to the lrc.
  *
  * Return latest ctx timestamp. With support for active contexts, the
- * calculation may bb slightly racy, so follow a read-again logic to ensure that
+ * calculation may be slightly racy, so follow a read-again logic to ensure that
  * the context is still active before returning the right timestamp.
  *
  * Returns: New ctx timestamp value
  */
 u64 xe_lrc_timestamp(struct xe_lrc *lrc)
 {
-	u64 lrc_ts, reg_ts, new_ts;
+	u64 lrc_ts, reg_ts, new_ts = lrc->ctx_timestamp;
 	u32 engine_id;
 
 	lrc_ts = xe_lrc_ctx_timestamp(lrc);