linux-kernel - [PATCH v4 1/4] rtc: mc146818-lib: Adjust failure return code for mc146818_get

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Message-ID: <20231128053653.101798-2-mario.limonciello@amd.com>
Date:   Mon, 27 Nov 2023 23:36:50 -0600
From:   Mario Limonciello <mario.limonciello@....com>
To:     Mateusz Jończyk <mat.jonczyk@...pl>,
        Alessandro Zummo <a.zummo@...ertech.it>,
        Alexandre Belloni <alexandre.belloni@...tlin.com>
CC:     "open list:REAL TIME CLOCK (RTC) SUBSYSTEM" 
        <linux-rtc@...r.kernel.org>,
        open list <linux-kernel@...r.kernel.org>,
        <linux-pm@...r.kernel.org>, <tobrohl@...il.com>,
        <aalsing@...il.com>, <Dhaval.Giani@....com>, <xmb8dsv4@...il.com>,
        <x86@...nel.org>, <dhaval.giani@...il.com>,
        Dave Hansen <dave.hansen@...ux.intel.com>,
        Borislav Petkov <bp@...en8.de>,
        "H . Peter Anvin" <hpa@...or.com>,
        Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>,
        Mario Limonciello <mario.limonciello@....com>
Subject: [PATCH v4 1/4] rtc: mc146818-lib: Adjust failure return code for mc146818_get_time()

mc146818_get_time() calls mc146818_avoid_UIP() to avoid fetching the
time while RTC update is in progress (UIP). When this fails, the return
code is -EIO, but actually there was no IO failure.

The reason for the return from mc146818_avoid_UIP() is that the UIP
wasn't cleared in the time period. Adjust the return code to -ETIMEDOUT
to match the behavior.

Tested-by: Mateusz Jończyk <mat.jonczyk@...pl>
Reviewed-by: Mateusz Jończyk <mat.jonczyk@...pl>
Acked-by: Mateusz Jończyk <mat.jonczyk@...pl>
Cc: stable@...r.kernel.org
Fixes: 2a61b0ac5493 ("rtc: mc146818-lib: refactor mc146818_get_time")
Signed-off-by: Mario Limonciello <mario.limonciello@....com>
---
v2->v3:
 * Add tags
v1->v2:
 * Add stable and fixes tag
---
 drivers/rtc/rtc-mc146818-lib.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/rtc/rtc-mc146818-lib.c b/drivers/rtc/rtc-mc146818-lib.c
index f1c09f1db044..43a28e82674e 100644
--- a/drivers/rtc/rtc-mc146818-lib.c
+++ b/drivers/rtc/rtc-mc146818-lib.c
@@ -138,7 +138,7 @@ int mc146818_get_time(struct rtc_time *time)
 
 	if (!mc146818_avoid_UIP(mc146818_get_time_callback, &p)) {
 		memset(time, 0, sizeof(*time));
-		return -EIO;
+		return -ETIMEDOUT;
 	}
 
 	if (!(p.ctrl & RTC_DM_BINARY) || RTC_ALWAYS_BCD)
-- 
2.34.1