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Date:   Sun, 3 Dec 2023 22:37:08 +0100
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From:   =?UTF-8?Q?Mateusz_Jo=C5=84czyk?= <mat.jonczyk@o2.pl>
Subject: Re: [PATCH v4 3/4] rtc: Add support for configuring the UIP timeout
 for RTC reads
To:     Mario Limonciello <mario.limonciello@amd.com>,
        Alessandro Zummo <a.zummo@towertech.it>,
        Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc:     "open list:REAL TIME CLOCK (RTC) SUBSYSTEM" 
        <linux-rtc@vger.kernel.org>,
        open list <linux-kernel@vger.kernel.org>,
        linux-pm@vger.kernel.org, tobrohl@gmail.com, aalsing@gmail.com,
        Dhaval.Giani@amd.com, xmb8dsv4@gmail.com, x86@kernel.org,
        dhaval.giani@gmail.com, Dave Hansen <dave.hansen@linux.intel.com>,
        Borislav Petkov <bp@alien8.de>,
        "H . Peter Anvin" <hpa@zytor.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>
References: <20231128053653.101798-1-mario.limonciello@amd.com>
 <20231128053653.101798-4-mario.limonciello@amd.com>
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// resending - first message was rejected as HTML-formatted

W dniu 28.11.2023 o 06:36, Mario Limonciello pisze:
> The UIP timeout is hardcoded to 10ms for all RTC reads, but in some
> contexts this might not be enough time. Add a timeout parameter to
> mc146818_get_time() and mc146818_get_time_callback().
>
> If UIP timeout is configured by caller to be >=100 ms and a call
> takes this long, log a warning.
>
> Make all callers use 10ms to ensure no functional changes.
>
> Cc: stable@vger.kernel.org # 6.1.y
> Fixes: ec5895c0f2d8 ("rtc: mc146818-lib: extract mc146818_avoid_UIP")
> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
> ---
> v3->v4:
>  * Change label
>  * Logic adjustment for for loop
>  * Fix pr_warn variable
> v2->v3:
>  * Logic adjustments
>  * Clarify warning message
> v1->v2:
>  * Add a warning if 100ms or more
>  * Add stable and fixes tags
>
Hello,

Tested-by: Mateusz Jończyk <mat.jonczyk@o2.pl>
Reviewed-by: Mateusz Jończyk <mat.jonczyk@o2.pl>
Acked-by: Mateusz Jończyk <mat.jonczyk@o2.pl>

I have retested the whole series on 2 computers
(not affected by the bug, resp. with / without HPET IRQ emulation).

Thank you for this patch series.

@Alexandre would it be possible to submit it for Linux 6.7?
There were several problem reports and it is marked for stable.

Greetings,

Mateusz