linux-kernel - Re: [PATCH v1 5/5] ASoC: tegra30: i2s: Add reset control

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

Date:   Wed, 3 Mar 2021 11:28:44 +0300
From:   Dmitry Osipenko <digetx@...il.com>
To:     Thierry Reding <thierry.reding@...il.com>,
        Jonathan Hunter <jonathanh@...dia.com>,
        Mark Brown <broonie@...nel.org>, Takashi Iwai <tiwai@...e.com>,
        Jaroslav Kysela <perex@...ex.cz>,
        Philipp Zabel <p.zabel@...gutronix.de>,
        Paul Fertser <fercerpav@...il.com>
Cc:     alsa-devel@...a-project.org, devicetree@...r.kernel.org,
        linux-tegra@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v1 5/5] ASoC: tegra30: i2s: Add reset control

02.03.2021 14:21, Dmitry Osipenko пишет:
> The I2S reset may be asserted at a boot time. Tegra30 I2S driver doesn't
> manage the reset control and currently it happens to work because reset
> is implicitly deasserted by the Tegra AHUB driver, but the reset of I2C
> controller should be synchronous and I2S clock is disabled when AHUB is
> reset. Add reset control to the Tegra30 I2S driver.
> 
> Note that I2S reset was always specified in Tegra30+ device-trees, hence
> DTB ABI changes aren't required. Also note that AHUB touches I2S resets,
> hence AHUB resets are now requested in a released state, allowing both
> drivers to control the I2S resets together.
> 
> Signed-off-by: Dmitry Osipenko <digetx@...il.com>
> ---
>  sound/soc/tegra/tegra30_ahub.c | 14 ++++++++++---
>  sound/soc/tegra/tegra30_i2s.c  | 36 +++++++++++++++++++++++++++++++++-
>  sound/soc/tegra/tegra30_i2s.h  |  1 +
>  3 files changed, 47 insertions(+), 4 deletions(-)

...
> @@ -579,7 +587,7 @@ static int tegra30_ahub_probe(struct platform_device *pdev)
>  	if (ret)
>  		return ret;
>  
> -	ahub->reset = devm_reset_control_array_get_exclusive(&pdev->dev);
> +	ahub->reset = devm_reset_control_array_get_exclusive_released(&pdev->dev);

Thinking a bit more about this, it looks like we actually want something
like:

	devm_reset_control_array_get_exclusive_released_named()

that will request resets by given names and in a given order, similarly
to devm_clk_bulk_get(). This will be very handy for both Tegra audio and
GPU drivers. I'll prepare a v2 if there are no objections.