dri-devel Archive on lore.kernel.org
 help / color / mirror / Atom feed
From: Russell King <rmk+kernel@arm.linux.org.uk>
To: Jean-Francois Moine <moinejf@free.fr>
Cc: dri-devel@lists.freedesktop.org
Subject: [PATCH] drm/i2c: tda998x: potentially faster polling for edid
Date: Mon, 03 Mar 2014 18:01:34 +0000	[thread overview]
Message-ID: <E1WKXBG-0003gB-GK@rmk-PC.arm.linux.org.uk> (raw)

One of Jean-Francois patches changed the EDID polling to once every
10ms for 10 interations, whereas the original code did 1ms for 100
interations.  This appears to cause boot-time detection to take
slightly - but noticably - longer.  Revert this change.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
Jean,

I'm not sure why you made the change along with adding IRQ support in
"drm/i2c: tda998x: use irq for connection status and EDID read" - you
didn't include any commentry as to why you made this change.  However,
we shouldn't write code assuming HZ=100 - where this kind of thing
matters, we should come up with better solutions (eg, using jiffy-based
timeouts if we want to timeout after a set period of time.)

I'm not sure whether one or other really is faster, it's just a
perception I have.  Anyway, let's just revert back to the original
code for the non-IRQ case, and maybe improve it later.

 drivers/gpu/drm/i2c/tda998x_drv.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i2c/tda998x_drv.c b/drivers/gpu/drm/i2c/tda998x_drv.c
index 40c4f658abfb..956d857ee2c9 100644
--- a/drivers/gpu/drm/i2c/tda998x_drv.c
+++ b/drivers/gpu/drm/i2c/tda998x_drv.c
@@ -1041,8 +1041,8 @@ static int read_edid_block(struct tda998x_priv *priv, uint8_t *buf, int blk)
 			return i;
 		}
 	} else {
-		for (i = 10; i > 0; i--) {
-			msleep(10);
+		for (i = 100; i > 0; i--) {
+			msleep(1);
 			ret = reg_read(priv, REG_INT_FLAGS_2);
 			if (ret < 0)
 				return ret;
-- 
1.8.3.1

             reply	other threads:[~2014-03-03 18:01 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-03-03 18:01 Russell King [this message]
2014-03-06 19:32 ` [PATCH] drm/i2c: tda998x: potentially faster polling for edid Jean-Francois Moine

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=E1WKXBG-0003gB-GK@rmk-PC.arm.linux.org.uk \
    --to=rmk+kernel@arm.linux.org.uk \
    --cc=dri-devel@lists.freedesktop.org \
    --cc=moinejf@free.fr \
    /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