From: vipoll <vipoll@mainlining.org>
To: heikki.krogerus@linux.intel.com, gregkh@linuxfoundation.org
Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
~postmarketos/upstreaming@lists.sr.ht,
Victor Paul <vipoll@mainlining.org>,
stable@vger.kernel.org
Subject: [PATCH] usb: typec: fsa4480: Add chip id read retry loop
Date: Mon, 11 May 2026 16:22:46 +0400 [thread overview]
Message-ID: <20260511122246.31673-1-vipoll@mainlining.org> (raw)
From: Victor Paul <vipoll@mainlining.org>
The first read attempt may fail on some devices (e.g. Xiaomi Pad 6)
Cc: stable@vger.kernel.org
Signed-off-by: Victor Paul <vipoll@mainlining.org>
---
drivers/usb/typec/mux/fsa4480.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/drivers/usb/typec/mux/fsa4480.c b/drivers/usb/typec/mux/fsa4480.c
index c54e42c7e6a1..ae496c0fa805 100644
--- a/drivers/usb/typec/mux/fsa4480.c
+++ b/drivers/usb/typec/mux/fsa4480.c
@@ -256,6 +256,7 @@ static int fsa4480_probe(struct i2c_client *client)
struct typec_switch_desc sw_desc = { };
struct typec_mux_desc mux_desc = { };
struct fsa4480 *fsa;
+ int retries = 5;
int val = 0;
int ret;
@@ -278,7 +279,12 @@ static int fsa4480_probe(struct i2c_client *client)
if (ret && ret != -ENODEV)
return dev_err_probe(dev, ret, "Failed to get regulator\n");
- ret = regmap_read(fsa->regmap, FSA4480_DEVICE_ID, &val);
+ do {
+ ret = regmap_read(fsa->regmap, FSA4480_DEVICE_ID, &val);
+ if (!ret)
+ break;
+ usleep_range(1000, 1200);
+ } while (retries--);
if (ret)
return dev_err_probe(dev, -ENODEV, "FSA4480 not found\n");
--
2.52.0
next reply other threads:[~2026-05-11 12:26 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-05-11 12:22 vipoll [this message]
2026-05-11 12:29 ` [PATCH] usb: typec: fsa4480: Add chip id read retry loop Greg KH
2026-05-11 12:29 ` Greg KH
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=20260511122246.31673-1-vipoll@mainlining.org \
--to=vipoll@mainlining.org \
--cc=gregkh@linuxfoundation.org \
--cc=heikki.krogerus@linux.intel.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-usb@vger.kernel.org \
--cc=stable@vger.kernel.org \
--cc=~postmarketos/upstreaming@lists.sr.ht \
/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