Fix timeout issue on some Ice Lake servers, where mail box command is
timing out before the response,
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@xxxxxxxxxxxxxxx>
---
.../x86/intel_speed_select_if/isst_if_mbox_pci.c | 11 +++++------
1 file changed, 5 insertions(+), 6 deletions(-)
diff --git a/drivers/platform/x86/intel_speed_select_if/isst_if_mbox_pci.c b/drivers/platform/x86/intel_speed_select_if/isst_if_mbox_pci.c
index de4169d0796b..d84e2174cbde 100644
--- a/drivers/platform/x86/intel_speed_select_if/isst_if_mbox_pci.c
+++ b/drivers/platform/x86/intel_speed_select_if/isst_if_mbox_pci.c
@@ -21,13 +21,12 @@
#define PUNIT_MAILBOX_BUSY_BIT 31
/*
- * Commands has variable amount of processing time. Most of the commands will
- * be done in 0-3 tries, but some takes up to 50.
- * The real processing time was observed as 25us for the most of the commands
- * at 2GHz. It is possible to optimize this count taking samples on customer
- * systems.
+ * The average time to complete some commands is about 40us. The current
+ * count is enough to satisfy 40us. But when the firmware is very busy, this
+ * causes timeout occasionally. So increase to deal with some worst case
+ * scenarios. Most of the command still complete in few us.
*/
-#define OS_MAILBOX_RETRY_COUNT 50
+#define OS_MAILBOX_RETRY_COUNT 100
struct isst_if_device {
struct mutex mutex;
--
2.25.4
