From: wens@csie.org (Chen-Yu Tsai)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] drm/sun4i: tcon: Initialize regmap after enabling bus clocks
Date: Wed, 16 Nov 2016 17:37:32 +0800 [thread overview]
Message-ID: <20161116093732.12828-2-wens@csie.org> (raw)
In-Reply-To: <20161116093732.12828-1-wens@csie.org>
If we attempt to read/write the TCON registers before the bus clock
is enabled, those accesses get ignored.
In practice this almost never occurs because U-boot had already enabled
the bus clock as part of its firmware provided framebuffer (simplefb).
Fixes: 9026e0d122ac ("drm: Add Allwinner A10 Display Engine support")
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
---
I was looking around the DRM driver and noticed this sequence was off.
---
drivers/gpu/drm/sun4i/sun4i_tcon.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/sun4i/sun4i_tcon.c b/drivers/gpu/drm/sun4i/sun4i_tcon.c
index c6afb2448655..8c2db65ea229 100644
--- a/drivers/gpu/drm/sun4i/sun4i_tcon.c
+++ b/drivers/gpu/drm/sun4i/sun4i_tcon.c
@@ -506,16 +506,16 @@ static int sun4i_tcon_bind(struct device *dev, struct device *master,
return ret;
}
- ret = sun4i_tcon_init_regmap(dev, tcon);
+ ret = sun4i_tcon_init_clocks(dev, tcon);
if (ret) {
- dev_err(dev, "Couldn't init our TCON regmap\n");
+ dev_err(dev, "Couldn't init our TCON clocks\n");
goto err_assert_reset;
}
- ret = sun4i_tcon_init_clocks(dev, tcon);
+ ret = sun4i_tcon_init_regmap(dev, tcon);
if (ret) {
- dev_err(dev, "Couldn't init our TCON clocks\n");
- goto err_assert_reset;
+ dev_err(dev, "Couldn't init our TCON regmap\n");
+ goto err_free_clocks;
}
ret = sun4i_tcon_init_irq(dev, tcon);
--
2.10.2
next prev parent reply other threads:[~2016-11-16 9:37 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-11-16 9:37 [PATCH] drm/sun4i: Only count TCON endpoints as valid outputs Chen-Yu Tsai
2016-11-16 9:37 ` Chen-Yu Tsai [this message]
2016-11-17 19:05 ` [PATCH] drm/sun4i: tcon: Initialize regmap after enabling bus clocks Maxime Ripard
2016-11-18 2:09 ` Chen-Yu Tsai
2016-11-17 19:02 ` [PATCH] drm/sun4i: Only count TCON endpoints as valid outputs Maxime Ripard
2016-11-18 2:22 ` Chen-Yu Tsai
2016-11-22 15:37 ` Maxime Ripard
2016-11-23 14:19 ` Chen-Yu Tsai
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=20161116093732.12828-2-wens@csie.org \
--to=wens@csie.org \
--cc=linux-arm-kernel@lists.infradead.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).