All of lore.kernel.org
 help / color / mirror / Atom feed
From: John Keeping <john@metanate.com>
To: linux-input@vger.kernel.org
Cc: John Keeping <john@metanate.com>,
	Dmitry Torokhov <dmitry.torokhov@gmail.com>,
	Geert Uytterhoeven <geert+renesas@glider.be>,
	linux-kernel@vger.kernel.org
Subject: [PATCH] Input: st1232 - increase "wait ready" timeout
Date: Wed, 29 Sep 2021 16:26:08 +0100	[thread overview]
Message-ID: <20210929152609.2421483-1-john@metanate.com> (raw)

I have a ST1633 touch controller which fails to probe due to a timeout
waiting for the controller to become ready.  Increasing the minimum
delay to 100ms ensures that the probe sequence completes successfully.

The ST1633 datasheet says nothing about the maximum delay here and the
ST1232 I2C protocol document says "wait until" with no notion of a
timeout.

Since this only runs once during probe, being generous with the timout
seems reasonable and most likely the device will become ready
eventually.

(It may be worth noting that I saw this issue with a PREEMPT_RT patched
kernel which probably has tighter wakeups from usleep_range() than other
preemption models.)

Fixes: f605be6a57b4 ("Input: st1232 - wait until device is ready before reading resolution")
Signed-off-by: John Keeping <john@metanate.com>
---
 drivers/input/touchscreen/st1232.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/input/touchscreen/st1232.c b/drivers/input/touchscreen/st1232.c
index 6abae665ca71..9d1dea6996a2 100644
--- a/drivers/input/touchscreen/st1232.c
+++ b/drivers/input/touchscreen/st1232.c
@@ -92,7 +92,7 @@ static int st1232_ts_wait_ready(struct st1232_ts_data *ts)
 	unsigned int retries;
 	int error;
 
-	for (retries = 10; retries; retries--) {
+	for (retries = 100; retries; retries--) {
 		error = st1232_ts_read_data(ts, REG_STATUS, 1);
 		if (!error) {
 			switch (ts->read_buf[0]) {
-- 
2.33.0


             reply	other threads:[~2021-09-29 15:26 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-09-29 15:26 John Keeping [this message]
2021-09-29 17:40 ` [PATCH] Input: st1232 - increase "wait ready" timeout Geert Uytterhoeven
2021-10-06 18:08 ` Dmitry Torokhov

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=20210929152609.2421483-1-john@metanate.com \
    --to=john@metanate.com \
    --cc=dmitry.torokhov@gmail.com \
    --cc=geert+renesas@glider.be \
    --cc=linux-input@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.