linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Boris Brezillon <boris.brezillon@free-electrons.com>
To: Marcel Holtmann <marcel@holtmann.org>,
	Gustavo Padovan <gustavo@padovan.org>,
	Johan Hedberg <johan.hedberg@gmail.com>,
	linux-bluetooth@vger.kernel.org
Cc: linux-kernel@vger.kernel.org, jason.abele@gmail.com,
	Boris Brezillon <boris.brezillon@free-electrons.com>
Subject: [PATCH 4/4] Bluetooth: hci_ldisc: make sure we don't loose HCI_UART_TX_WAKEUP events
Date: Fri, 19 Aug 2016 09:38:47 +0200	[thread overview]
Message-ID: <1471592327-14133-5-git-send-email-boris.brezillon@free-electrons.com> (raw)
In-Reply-To: <1471592327-14133-1-git-send-email-boris.brezillon@free-electrons.com>

The HCI_UART_TX_WAKEUP flag checking is racy and some HCI_UART_TX_WAKEUP
events can be lost.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
---
 drivers/bluetooth/hci_ldisc.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/drivers/bluetooth/hci_ldisc.c b/drivers/bluetooth/hci_ldisc.c
index 27f73294edcb..ee7b25f1c6ce 100644
--- a/drivers/bluetooth/hci_ldisc.c
+++ b/drivers/bluetooth/hci_ldisc.c
@@ -172,6 +172,17 @@ restart:
 		goto restart;
 
 	clear_bit(HCI_UART_SENDING, &hu->tx_state);
+
+	/*
+	 * One last check to make sure hci_uart_tx_wakeup() did not set
+	 * HCI_UART_TX_WAKEUP while we where clearing HCI_UART_SENDING.
+	 * The work might have been scheduled by someone else in the
+	 * meantime, in this case we return directly.
+	 */
+	if (test_bit(HCI_UART_TX_WAKEUP, &hu->tx_state) &&
+	    !test_and_set_bit(HCI_UART_SENDING, &hu->tx_state))
+		goto restart;
+
 }
 
 static void hci_uart_init_work(struct work_struct *work)
-- 
2.7.4

  parent reply	other threads:[~2016-08-19  7:38 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-08-19  7:38 [PATCH 0/4] Bluetooth: hci_uart: various fixes Boris Brezillon
2016-08-19  7:38 ` [PATCH 1/4] Bluetooth: hci_ldisc: fix a race in the hdev closing path Boris Brezillon
2016-08-30 16:53   ` Marcel Holtmann
2016-08-30 17:08     ` Boris Brezillon
2016-08-19  7:38 ` [PATCH 2/4] Bluetooth: hci_h5: fix a race in the " Boris Brezillon
2016-08-30 16:54   ` Marcel Holtmann
2016-08-19  7:38 ` [PATCH 3/4] Bluetooth: hci_ldisc: don't release resources in hci_uart_init_work() Boris Brezillon
2016-08-19  7:38 ` Boris Brezillon [this message]
2016-08-30 16:53   ` [PATCH 4/4] Bluetooth: hci_ldisc: make sure we don't loose HCI_UART_TX_WAKEUP events Marcel Holtmann
2016-08-30 17:10     ` Boris Brezillon
2016-08-30 13:26 ` [PATCH 0/4] Bluetooth: hci_uart: various fixes Boris Brezillon
2016-08-30 16:48 ` Marcel Holtmann
2016-08-30 17:22   ` Boris Brezillon
2016-08-31  2:08     ` Marcel Holtmann

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=1471592327-14133-5-git-send-email-boris.brezillon@free-electrons.com \
    --to=boris.brezillon@free-electrons.com \
    --cc=gustavo@padovan.org \
    --cc=jason.abele@gmail.com \
    --cc=johan.hedberg@gmail.com \
    --cc=linux-bluetooth@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=marcel@holtmann.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).