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From: Sameer Pujar <spujar@nvidia.com>
To: Dmitry Osipenko <digetx@gmail.com>, <broonie@kernel.org>
Cc: <jonathanh@nvidia.com>, <linux-kernel@vger.kernel.org>,
	<linux-tegra@vger.kernel.org>
Subject: Re: [PATCH v3] regmap: add iopoll-like atomic polling macro
Date: Thu, 9 Jan 2020 12:54:31 +0530	[thread overview]
Message-ID: <b9f5459f-007e-3139-a3cf-c7dfd3fc335a@nvidia.com> (raw)
In-Reply-To: <fa5198bf-0001-3a57-017f-1b40e0188606@gmail.com>


On 1/9/2020 11:30 AM, Dmitry Osipenko wrote:
> External email: Use caution opening links or attachments
>
>
> 09.01.2020 08:09, Sameer Pujar пишет:
>> This patch adds a macro 'regmap_read_poll_timeout_atomic' that works
>> similar to 'readx_poll_timeout_atomic' defined in linux/iopoll.h; This
>> is atomic version of already available 'regmap_read_poll_timeout' macro.
>>
>> It should be noted that above atomic macro cannot be used by all regmaps.
>> If the regmap is set up for atomic use (flat or no cache and MMIO) then
>> only it can use.
>>
>> Signed-off-by: Sameer Pujar <spujar@nvidia.com>
>> ---
> Could you please explain what is the targeted use-case here?

I was trying to use regmap_read_poll_timeout() to poll for status change 
of a register. This resulted in "BUG: scheduling while atomic". The 
callback function, in which I was trying to use the macro, runs in 
atomic context. Hence new atomic macro is added. I was checking ALSA 
playback/capture and trigger() callback had to monitor some register status.

In general, the new macro can be used in atomic callbacks where regmap 
interface is used and polling is required.


  reply	other threads:[~2020-01-09  7:24 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-01-09  5:09 [PATCH v3] regmap: add iopoll-like atomic polling macro Sameer Pujar
2020-01-09  6:00 ` Dmitry Osipenko
2020-01-09  7:24   ` Sameer Pujar [this message]
2020-01-09 13:57     ` Dmitry Osipenko
2020-01-10  4:50       ` Sameer Pujar
2020-01-10 22:07         ` Dmitry Osipenko
2020-01-09 21:30 ` Applied "regmap: add iopoll-like atomic polling macro" to the regmap tree Mark Brown

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