linux-kernel - Re: [PATCH v2] regmap-irq: Use regmap_irq_update_bits instead of regmap

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Date:   Tue, 8 Feb 2022 13:29:55 +0100
From:   Marek Szyprowski <m.szyprowski@...sung.com>
To:     Prasad Kumpatla <quic_pkumpatl@...cinc.com>,
        Mark Brown <broonie@...nel.org>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        "Rafael J. Wysocki" <rafael@...nel.org>,
        linux-kernel@...r.kernel.org,
        Krzysztof Kozlowski <krzk@...nel.org>,
        'Linux Samsung SOC' <linux-samsung-soc@...r.kernel.org>
Subject: Re: [PATCH v2] regmap-irq: Use regmap_irq_update_bits instead of
 regmap_write

Hi Prasad,

On 19.01.2022 15:29, Prasad Kumpatla wrote:
> With the existing logic by using regmap_write() all the bits in
> the register are being updated which is not expected. To update only the
> interrupt raised bit and not tocuhing other bits, replace regmap_write()
> with regmap_irq_update_bits().
>
> This patch is to fix the issue observed in MBHC button press/release events.
>
> Fixes: 3a6f0fb7b8eb ("regmap: irq: Add support to clear ack registers")
> Signed-off-by: Prasad Kumpatla <quic_pkumpatl@...cinc.com>

There is something wrong with this patch. Since it landed in linux-next 
(20220204) I get an interrupt storm on two of my test devices:

1. ARM 32bit Exynos4412-based Trats2 ("wm8994-codec wm8994-codec: FIFO 
error" message)

2. ARM 64bit Exynos5433-based TM2e ("arizona spi1.0: Mixer dropped 
sample" message)

Definitely the interrupts are not acknowledged properly. Once I find 
some spare time, I will check it further which regmap configuration 
triggers the issue, but it is definitely related to this patch. 
Reverting it on top of current linux-next fixes the issue.

> ---
> Changes Since V1:
> -- Update commit message.
>
>   drivers/base/regmap/regmap-irq.c | 52 ++++++++++++++++++--------------
>   1 file changed, 29 insertions(+), 23 deletions(-)
>
> ...

Best regards
-- 
Marek Szyprowski, PhD
Samsung R&D Institute Poland