[PATCH v8 05/10] misc: amd-sbi: Optimize the wait condition for mailbox command completion

Akshay Gupta
2025-04-11T13:32:07Z

- optimize the wait condition to indicate command completion
by replacing the do while loop with regmap subsystem API
regmap_read_poll_timeout()

Reviewed-by: Naveen Krishna Chatradhi <naveenkrishna.chatradhi@amd.com>
Signed-off-by: Akshay Gupta <akshay.gupta@amd.com>
---
Changes since v4:
- Previously patch 3

Changes since v3:
- New patch as per suggestion from Arnd

drivers/misc/amd-sbi/rmi-core.c | 19 ++++---------------
1 file changed, 4 insertions(+), 15 deletions(-)

diff --git a/drivers/misc/amd-sbi/rmi-core.c b/drivers/misc/amd-sbi/rmi-core.c
index 663ab9176d95..1d5e2556ab88 100644
--- a/drivers/misc/amd-sbi/rmi-core.c
+++ b/drivers/misc/amd-sbi/rmi-core.c
@@ -23,7 +23,7 @@ int rmi_mailbox_xfer(struct sbrmi_data *data,
struct sbrmi_mailbox_msg *msg)
{
unsigned int bytes;
- int i, ret, retry = 10;
+ int i, ret;
int sw_status;
u8 byte;

@@ -64,21 +64,10 @@ int rmi_mailbox_xfer(struct sbrmi_data *data,
* an ALERT (if enabled) to initiator (BMC) to indicate completion
* of the requested command
*/
- do {
- ret = regmap_read(data->regmap, SBRMI_STATUS, &sw_status);
- if (sw_status < 0) {
- ret = sw_status;
- goto exit_unlock;
- }
- if (sw_status & SW_ALERT_MASK)
- break;
- usleep_range(50, 100);
- } while (retry--);
-
- if (retry < 0) {
- ret = -EIO;
+ ret = regmap_read_poll_timeout(data->regmap, SBRMI_STATUS, sw_status,
+ sw_status & SW_ALERT_MASK, 500, 2000000);
+ if (ret)
goto exit_unlock;
- }

/*
* For a read operation, the initiator (BMC) reads the firmware
--
2.25.1