linux-kernel - [PATCH 1/3] hwmon: pmbus: Reduce clear fault page invocations

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:   Thu, 17 Aug 2023 11:25:24 +0200
From:   Naresh Solanki <naresh.solanki@...ements.com>
To:     Guenter Roeck <linux@...ck-us.net>,
        Jean Delvare <jdelvare@...e.com>
Cc:     Patrick Rudolph <patrick.rudolph@...ements.com>,
        Naresh Solanki <Naresh.Solanki@...ements.com>,
        linux-hwmon@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH 1/3] hwmon: pmbus: Reduce clear fault page invocations

From: Patrick Rudolph <patrick.rudolph@...ements.com>

Observing I2C traffic revealed consecutive transmission of CLEAR_FAULT
commands. While this doesn't cause issues, it extends driver probe time.

Avoid invoking pmbus_clear_fault_page for virtual registers, as they're
managed by the driver, not the chip.

TEST: Verified using an I2C bus analyzer that only one CLEAR_FAULT
      command is send instead 5 in a row.

Signed-off-by: Patrick Rudolph <patrick.rudolph@...ements.com>
Signed-off-by: Naresh Solanki <Naresh.Solanki@...ements.com>
---
 drivers/hwmon/pmbus/pmbus_core.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c
index 69a4e62b6c8d..cbfabdd69056 100644
--- a/drivers/hwmon/pmbus/pmbus_core.c
+++ b/drivers/hwmon/pmbus/pmbus_core.c
@@ -561,7 +561,8 @@ static bool pmbus_check_register(struct i2c_client *client,
 		rv = pmbus_check_status_cml(client);
 	if (rv < 0 && (data->flags & PMBUS_READ_STATUS_AFTER_FAILED_CHECK))
 		data->read_status(client, -1);
-	pmbus_clear_fault_page(client, -1);
+	if (reg < PMBUS_VIRT_BASE)
+		pmbus_clear_fault_page(client, -1);
 	return rv >= 0;
 }
 

base-commit: fc8df28be7155ddcf8731b4c85fd3372811ba5ac
-- 
2.41.0