From: Thierry Reding <thierry.reding@gmail.com>
To: Dmitry Osipenko <digetx@gmail.com>
Cc: Jonathan Hunter <jonathanh@nvidia.com>,
Sameer Pujar <spujar@nvidia.com>,
Peter Geis <pgwipeout@gmail.com>,
Nicolas Chauvet <kwizart@gmail.com>,
Takashi Iwai <tiwai@suse.com>, Jaroslav Kysela <perex@perex.cz>,
alsa-devel@alsa-project.org, linux-tegra@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v1 5/5] ASoC: tegra: ahub: Reset hardware properly
Date: Tue, 19 Jan 2021 18:34:30 +0100 [thread overview]
Message-ID: <YAcYJpb/Zf7IKZp5@ulmo> (raw)
In-Reply-To: <c2f3d149-0781-3d0a-1d68-f6820386e84d@gmail.com>
[-- Attachment #1: Type: text/plain, Size: 4044 bytes --]
On Mon, Jan 18, 2021 at 03:02:38AM +0300, Dmitry Osipenko wrote:
> 15.01.2021 18:44, Thierry Reding пишет:
> > On Tue, Jan 12, 2021 at 03:58:34PM +0300, Dmitry Osipenko wrote:
> >> Assert hardware reset before clocks are enabled and then de-assert it
> >> after clocks are enabled. This brings hardware into a predictable state
> >> and removes relying on implicit de-assertion of resets which is done by
> >> the clk driver.
> >>
> >> Tested-by: Peter Geis <pgwipeout@gmail.com>
> >> Tested-by: Nicolas Chauvet <kwizart@gmail.com>
> >> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
> >> ---
> >> sound/soc/tegra/tegra30_ahub.c | 33 ++++++++++++++++-----------------
> >> sound/soc/tegra/tegra30_ahub.h | 1 +
> >> 2 files changed, 17 insertions(+), 17 deletions(-)
> >>
> >> diff --git a/sound/soc/tegra/tegra30_ahub.c b/sound/soc/tegra/tegra30_ahub.c
> >> index 4dbb58f7ea36..246cf6a373a1 100644
> >> --- a/sound/soc/tegra/tegra30_ahub.c
> >> +++ b/sound/soc/tegra/tegra30_ahub.c
> >> @@ -65,10 +65,20 @@ static int tegra30_ahub_runtime_resume(struct device *dev)
> >> {
> >> int ret;
> >>
> >> + ret = reset_control_assert(ahub->reset);
> >> + if (ret)
> >> + return ret;
> >> +
> >> ret = clk_bulk_prepare_enable(ahub->nclocks, ahub->clocks);
> >> if (ret)
> >> return ret;
> >>
> >> + ret = reset_control_reset(ahub->reset);
> >> + if (ret) {
> >> + clk_bulk_disable_unprepare(ahub->nclocks, ahub->clocks);
> >> + return ret;
> >> + }
> >> +
> >> regcache_cache_only(ahub->regmap_apbif, false);
> >> regcache_cache_only(ahub->regmap_ahub, false);
> >>
> >> @@ -462,7 +472,6 @@ static int tegra30_ahub_probe(struct platform_device *pdev)
> >> {
> >> const struct of_device_id *match;
> >> const struct tegra30_ahub_soc_data *soc_data;
> >> - struct reset_control *rst;
> >> struct resource *res0;
> >> void __iomem *regs_apbif, *regs_ahub;
> >> int ret = 0;
> >> @@ -475,22 +484,6 @@ static int tegra30_ahub_probe(struct platform_device *pdev)
> >> return -EINVAL;
> >> soc_data = match->data;
> >>
> >> - /*
> >> - * The AHUB hosts a register bus: the "configlink". For this to
> >> - * operate correctly, all devices on this bus must be out of reset.
> >> - * Ensure that here.
> >> - */
> >> - rst = of_reset_control_array_get_exclusive(pdev->dev.of_node);
> >> - if (IS_ERR(rst)) {
> >> - dev_err(&pdev->dev, "Can't get reset: %p\n", rst);
> >> - return PTR_ERR(rst);
> >> - }
> >> -
> >> - ret = reset_control_deassert(rst);
> >> - reset_control_put(rst);
> >> - if (ret)
> >> - return ret;
> >> -
> >> ahub = devm_kzalloc(&pdev->dev, sizeof(struct tegra30_ahub),
> >> GFP_KERNEL);
> >> if (!ahub)
> >> @@ -507,6 +500,12 @@ static int tegra30_ahub_probe(struct platform_device *pdev)
> >> if (ret)
> >> return ret;
> >>
> >> + ahub->reset = devm_reset_control_array_get_exclusive(&pdev->dev);
> >> + if (IS_ERR(ahub->reset)) {
> >> + dev_err(&pdev->dev, "Can't get reset: %p\n", ahub->reset);
> >
> > I didn't notice that the prior patch already introduced this, but I'd
> > prefer for this to either be %pe so that the symbolic error name is
> > printed, or %ld with PTR_ERR(ahub->reset) to format this in a more
> > standard way that can be more easily grepped for and parsed.
>
> This is already fixed in v2. Good catch anyways, thanks.
>
> > It also seems like the prior patch that converts this to use
> > of_reset_control_array_get_exclusive() is a bit pointless now. Why not
> > just move to this directly instead?
>
> These are two independent changes. The previous patch fixed the missing
> resets, this patch changes the hardware initialization logic.
But moving to devm_reset_control_array_get_exclusive() isn't really part
of the hardware initialization logic change, right? So it's not strictly
related to the rest of this patch.
Anyway, I don't feel strongly about it being part of this patch, so feel
free to keep it here.
Thierry
[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 833 bytes --]
next prev parent reply other threads:[~2021-01-19 18:29 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-12 12:58 [PATCH v1 0/5] Clock and reset improvements for Tegra ALSA drivers Dmitry Osipenko
2021-01-12 12:58 ` [PATCH v1 1/5] ALSA: hda/tegra: Use clk_bulk helpers Dmitry Osipenko
2021-01-15 15:22 ` Thierry Reding
2021-01-17 23:31 ` Dmitry Osipenko
2021-01-19 17:31 ` Thierry Reding
2021-01-12 12:58 ` [PATCH v1 2/5] ALSA: hda/tegra: Reset hardware Dmitry Osipenko
2021-01-15 15:35 ` Thierry Reding
2021-01-17 23:39 ` Dmitry Osipenko
2021-01-19 17:30 ` Thierry Reding
2021-01-12 12:58 ` [PATCH v1 3/5] ASoC: tegra: ahub: Use of_reset_control_array_get_exclusive() Dmitry Osipenko
2021-01-15 15:37 ` Thierry Reding
2021-01-17 23:57 ` Dmitry Osipenko
2021-01-12 12:58 ` [PATCH v1 4/5] ASoC: tegra: ahub: Use clk_bulk helpers Dmitry Osipenko
2021-01-15 15:38 ` Thierry Reding
2021-01-12 12:58 ` [PATCH v1 5/5] ASoC: tegra: ahub: Reset hardware properly Dmitry Osipenko
2021-01-15 13:02 ` Dmitry Osipenko
2021-01-15 15:44 ` Thierry Reding
2021-01-18 0:02 ` Dmitry Osipenko
2021-01-19 17:34 ` Thierry Reding [this message]
2021-01-15 10:18 ` [PATCH v1 0/5] Clock and reset improvements for Tegra ALSA drivers Takashi Iwai
2021-01-15 10:52 ` Ben Dooks
2021-01-15 12:59 ` Dmitry Osipenko
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=YAcYJpb/Zf7IKZp5@ulmo \
--to=thierry.reding@gmail.com \
--cc=alsa-devel@alsa-project.org \
--cc=digetx@gmail.com \
--cc=jonathanh@nvidia.com \
--cc=kwizart@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-tegra@vger.kernel.org \
--cc=perex@perex.cz \
--cc=pgwipeout@gmail.com \
--cc=spujar@nvidia.com \
--cc=tiwai@suse.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).