From: Jagan Teki <jagan@amarulasolutions.com>
To: Chen-Yu Tsai <wens@csie.org>
Cc: devicetree <devicetree@vger.kernel.org>,
Jernej Skrabec <jernej.skrabec@siol.net>,
Maxime Ripard <maxime.ripard@bootlin.com>,
linux-kernel <linux-kernel@vger.kernel.org>,
dri-devel <dri-devel@lists.freedesktop.org>,
David Airlie <airlied@linux.ie>,
linux-sunxi <linux-sunxi@googlegroups.com>,
Daniel Vetter <daniel@ffwll.ch>,
Michael Trimarchi <michael@amarulasolutions.com>,
linux-amarula <linux-amarula@amarulasolutions.com>,
linux-arm-kernel <linux-arm-kernel@lists.infradead.org>
Subject: Re: [linux-sunxi] [PATCH v2 5/9] drm/sun4i: tcon_top: Register clock gates in probe
Date: Mon, 17 Jun 2019 15:59:50 +0530 [thread overview]
Message-ID: <CAMty3ZDRYBPKrGQxAZoB+trFiDLJ5BxDfNUOnPzgd+UWcpwCoQ@mail.gmail.com> (raw)
In-Reply-To: <CAGb2v669MprYgy2wc_a7Kz8VpzzNGZxDxsj0z_Ujx5bV25+AWQ@mail.gmail.com>
On Sun, Jun 16, 2019 at 11:01 AM Chen-Yu Tsai <wens@csie.org> wrote:
>
> On Sat, Jun 15, 2019 at 12:44 AM Jagan Teki <jagan@amarulasolutions.com> wrote:
> >
> > TCON TOP have clock gates for TV0, TV1, dsi and right
> > now these are register during bind call.
> >
> > Of which, dsi clock gate would required during DPHY probe
> > but same can miss to get since tcon top is not bound at
> > that time.
> >
> > To solve, this circular dependency move the clock gate
> > registration from bind to probe so-that DPHY can get the
> > dsi gate clock on time.
> >
> > Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
> > ---
> > drivers/gpu/drm/sun4i/sun8i_tcon_top.c | 94 ++++++++++++++------------
> > 1 file changed, 49 insertions(+), 45 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/sun4i/sun8i_tcon_top.c b/drivers/gpu/drm/sun4i/sun8i_tcon_top.c
> > index 465e9b0cdfee..a8978b3fe851 100644
> > --- a/drivers/gpu/drm/sun4i/sun8i_tcon_top.c
> > +++ b/drivers/gpu/drm/sun4i/sun8i_tcon_top.c
> > @@ -124,7 +124,53 @@ static struct clk_hw *sun8i_tcon_top_register_gate(struct device *dev,
> > static int sun8i_tcon_top_bind(struct device *dev, struct device *master,
> > void *data)
> > {
> > - struct platform_device *pdev = to_platform_device(dev);
> > + struct sun8i_tcon_top *tcon_top = dev_get_drvdata(dev);
> > + int ret;
> > +
> > + ret = reset_control_deassert(tcon_top->rst);
> > + if (ret) {
> > + dev_err(dev, "Could not deassert ctrl reset control\n");
> > + return ret;
> > + }
> > +
> > + ret = clk_prepare_enable(tcon_top->bus);
> > + if (ret) {
> > + dev_err(dev, "Could not enable bus clock\n");
> > + goto err_assert_reset;
> > + }
>
> You have to de-assert the reset control and enable the clock before the
> clocks it provides are registered. Otherwise a consumer may come in and
> ask for the provided clock to be enabled, but since the TCON TOP's own
> reset and clock are still disabled, you can't actually access the registers
> that controls the provided clock.
These rst and bus are common reset and bus clocks not tcon top clocks
that are trying to register here. ie reason I have not moved it in
top.
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2019-06-17 10:30 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-14 16:43 [PATCH v2 0/9] drm/sun4i: Allwinner R40 MIPI-DSI support Jagan Teki
2019-06-14 16:43 ` [PATCH v2 1/9] dt-bindings: display: Add TCON LCD compatible for R40 Jagan Teki
2019-07-09 14:49 ` Rob Herring
2019-06-14 16:43 ` [PATCH v2 2/9] drm/sun4i: tcon: Add TCON LCD support " Jagan Teki
2019-06-14 16:43 ` [PATCH v2 3/9] ARM: dts: sun8i: r40: Use tcon top clock index macros Jagan Teki
2019-06-14 16:43 ` [PATCH v2 4/9] drm/sun4i: tcon_top: Use clock name " Jagan Teki
2019-06-14 16:43 ` [PATCH v2 5/9] drm/sun4i: tcon_top: Register clock gates in probe Jagan Teki
2019-06-16 5:31 ` [linux-sunxi] " Chen-Yu Tsai
2019-06-17 10:29 ` Jagan Teki [this message]
2019-06-18 7:19 ` Chen-Yu Tsai
2019-06-18 7:45 ` Jagan Teki
2019-06-18 7:53 ` Chen-Yu Tsai
2019-06-18 10:34 ` Jagan Teki
2019-06-18 10:54 ` Chen-Yu Tsai
2019-06-20 16:24 ` Jagan Teki
2019-06-21 8:00 ` Chen-Yu Tsai
2019-06-17 11:45 ` Maxime Ripard
2019-06-17 13:01 ` [linux-sunxi] " Chen-Yu Tsai
2019-06-17 14:54 ` Maxime Ripard
2019-06-18 7:12 ` Jagan Teki
2019-06-18 7:23 ` Chen-Yu Tsai
2019-06-18 7:46 ` Jagan Teki
2019-06-14 16:43 ` [PATCH v2 6/9] dt-bindings: sun6i-dsi: Add R40 MIPI-DSI compatible (w/ A64 fallback) Jagan Teki
2019-07-09 14:50 ` Rob Herring
2019-06-14 16:43 ` [PATCH v2 7/9] dt-bindings: sun6i-dsi: Add R40 DPHY compatible (w/ A31 fallback) Jagan Teki
2019-07-09 16:16 ` Rob Herring
2019-06-14 16:43 ` [PATCH v2 8/9] ARM: dts: sun8i: r40: Add MIPI DSI pipeline Jagan Teki
2019-06-14 16:43 ` [DO NOT MERGE] [PATCH v2 9/9] ARM: dts: sun8i-r40: bananapi-m2-ultra: Enable Bananapi S070WV20-CT16 DSI panel Jagan Teki
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=CAMty3ZDRYBPKrGQxAZoB+trFiDLJ5BxDfNUOnPzgd+UWcpwCoQ@mail.gmail.com \
--to=jagan@amarulasolutions.com \
--cc=airlied@linux.ie \
--cc=daniel@ffwll.ch \
--cc=devicetree@vger.kernel.org \
--cc=dri-devel@lists.freedesktop.org \
--cc=jernej.skrabec@siol.net \
--cc=linux-amarula@amarulasolutions.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-sunxi@googlegroups.com \
--cc=maxime.ripard@bootlin.com \
--cc=michael@amarulasolutions.com \
--cc=wens@csie.org \
/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).