linux-kernel - [PATCH v6 05/11] misc: amd-sbi: Optimize the wait condition for mailbox command completion

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Message-ID: <20250324145815.1026314-6-akshay.gupta@amd.com>
Date: Mon, 24 Mar 2025 14:58:09 +0000
From: Akshay Gupta <akshay.gupta@....com>
To: <linux-hwmon@...r.kernel.org>, <linux-kernel@...r.kernel.org>
CC: <linux@...ck-us.net>, <gregkh@...uxfoundation.org>, <arnd@...db.de>,
	<shyam-sundar.s-k@....com>, <gautham.shenoy@....com>,
	<mario.limonciello@....com>, <naveenkrishna.chatradhi@....com>,
	<anand.umarji@....com>, Akshay Gupta <akshay.gupta@....com>
Subject: [PATCH v6 05/11] misc: amd-sbi: Optimize the wait condition for mailbox command completion

- 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@....com>
Signed-off-by: Akshay Gupta <akshay.gupta@....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