From: Bjorn Andersson <bjorn.andersson@linaro.org>
To: Heikki Krogerus <heikki.krogerus@linux.intel.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Benjamin Berg <bberg@redhat.com>
Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH] usb: typec: ucsi: Clear pending after acking connector change
Date: Sat, 15 May 2021 21:09:53 -0700 [thread overview]
Message-ID: <20210516040953.622409-1-bjorn.andersson@linaro.org> (raw)
It's possible that the interrupt handler for the UCSI driver signals a
connector changes after the handler clears the PENDING bit, but before
it has sent the acknowledge request. The result is that the handler is
invoked yet again, to ack the same connector change.
At least some versions of the Qualcomm UCSI firmware will not handle the
second - "spurious" - acknowledgment gracefully. So make sure to not
clear the pending flag until the change is acknowledged.
Any connector changes coming in after the acknowledgment, that would
have the pending flag incorrectly cleared, would afaict be covered by
the subsequent connector status check.
Fixes: 217504a05532 ("usb: typec: ucsi: Work around PPM losing change information")
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
---
drivers/usb/typec/ucsi/ucsi.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/usb/typec/ucsi/ucsi.c b/drivers/usb/typec/ucsi/ucsi.c
index 282c3c825c13..f451ce0132a9 100644
--- a/drivers/usb/typec/ucsi/ucsi.c
+++ b/drivers/usb/typec/ucsi/ucsi.c
@@ -694,8 +694,8 @@ static void ucsi_handle_connector_change(struct work_struct *work)
ucsi_send_command(con->ucsi, command, NULL, 0);
/* 3. ACK connector change */
- clear_bit(EVENT_PENDING, &ucsi->flags);
ret = ucsi_acknowledge_connector_change(ucsi);
+ clear_bit(EVENT_PENDING, &ucsi->flags);
if (ret) {
dev_err(ucsi->dev, "%s: ACK failed (%d)", __func__, ret);
goto out_unlock;
--
2.29.2
next reply other threads:[~2021-05-16 4:10 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-16 4:09 Bjorn Andersson [this message]
2021-05-17 10:03 ` [PATCH] usb: typec: ucsi: Clear pending after acking connector change Heikki Krogerus
2021-05-17 12:15 ` Heikki Krogerus
2021-05-17 12:57 ` Benjamin Berg
2021-05-18 13:29 ` Heikki Krogerus
2021-05-18 18:04 ` Benjamin Berg
2021-05-19 11:33 ` Heikki Krogerus
2021-05-19 11:50 ` Benjamin Berg
2021-05-17 12:36 ` Benjamin Berg
2021-05-18 13:21 ` Heikki Krogerus
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=20210516040953.622409-1-bjorn.andersson@linaro.org \
--to=bjorn.andersson@linaro.org \
--cc=bberg@redhat.com \
--cc=gregkh@linuxfoundation.org \
--cc=heikki.krogerus@linux.intel.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-usb@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 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).