linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Johan Hovold <johan@kernel.org>
To: Rob Herring <robh@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Jiri Slaby <jslaby@suse.com>, Johan Hovold <johan@kernel.org>,
	Andrey Smirnov <andrew.smirnov@gmail.com>,
	linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH 3/4] serdev: make synchronous write helper interruptible
Date: Wed, 14 Nov 2018 16:09:03 +0100	[thread overview]
Message-ID: <20181114150904.19653-4-johan@kernel.org> (raw)
In-Reply-To: <20181114150904.19653-1-johan@kernel.org>

Allow the synchronous serdev_device_write() helper to be interrupted.

This is useful for cases where I/O is performed on behalf of user space
and we don't want to block indefinitely when using flow control.

Signed-off-by: Johan Hovold <johan@kernel.org>
---
 drivers/tty/serdev/core.c | 20 ++++++++++++++------
 include/linux/serdev.h    |  2 +-
 2 files changed, 15 insertions(+), 7 deletions(-)

diff --git a/drivers/tty/serdev/core.c b/drivers/tty/serdev/core.c
index ee4c40336633..c7006bbb793a 100644
--- a/drivers/tty/serdev/core.c
+++ b/drivers/tty/serdev/core.c
@@ -231,7 +231,7 @@ EXPORT_SYMBOL_GPL(serdev_device_write_buf);
 
 int serdev_device_write(struct serdev_device *serdev,
 			const unsigned char *buf, size_t count,
-			unsigned long timeout)
+			long timeout)
 {
 	struct serdev_controller *ctrl = serdev->ctrl;
 	int written = 0;
@@ -254,16 +254,24 @@ int serdev_device_write(struct serdev_device *serdev,
 		written += ret;
 		buf += ret;
 		count -= ret;
-	} while (count &&
-		 (timeout = wait_for_completion_timeout(&serdev->write_comp,
-							timeout)));
+
+		if (count == 0)
+			break;
+
+		timeout = wait_for_completion_interruptible_timeout(&serdev->write_comp,
+								    timeout);
+	} while (timeout > 0);
 	mutex_unlock(&serdev->write_lock);
 
 	if (ret < 0)
 		return ret;
 
-	if (timeout == 0 && written == 0)
-		return -ETIMEDOUT;
+	if (timeout <= 0 && written == 0) {
+		if (timeout == -ERESTARTSYS)
+			return -ERESTARTSYS;
+		else
+			return -ETIMEDOUT;
+	}
 
 	return written;
 }
diff --git a/include/linux/serdev.h b/include/linux/serdev.h
index f153b2c7f0cd..070bf4e92df7 100644
--- a/include/linux/serdev.h
+++ b/include/linux/serdev.h
@@ -210,7 +210,7 @@ void serdev_device_wait_until_sent(struct serdev_device *, long);
 int serdev_device_get_tiocm(struct serdev_device *);
 int serdev_device_set_tiocm(struct serdev_device *, int, int);
 void serdev_device_write_wakeup(struct serdev_device *);
-int serdev_device_write(struct serdev_device *, const unsigned char *, size_t, unsigned long);
+int serdev_device_write(struct serdev_device *, const unsigned char *, size_t, long);
 void serdev_device_write_flush(struct serdev_device *);
 int serdev_device_write_room(struct serdev_device *);
 
-- 
2.19.1


  parent reply	other threads:[~2018-11-14 15:10 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-11-14 15:09 [PATCH 0/4] serdev: make serdev_device_write() more usable Johan Hovold
2018-11-14 15:09 ` [PATCH 1/4] serdev: use zero to indicate infinite write timeout Johan Hovold
2018-11-14 15:09 ` [PATCH 2/4] serdev: make synchronous write return bytes written Johan Hovold
2018-11-19 15:15   ` Rob Herring
2018-11-20 17:09     ` Johan Hovold
2018-11-14 15:09 ` Johan Hovold [this message]
2018-11-14 15:09 ` [PATCH 4/4] serdev: document the write functions using kernel-doc Johan Hovold
2018-11-19 15:16 ` [PATCH 0/4] serdev: make serdev_device_write() more usable Rob Herring
2018-11-20 17:11   ` Johan Hovold

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=20181114150904.19653-4-johan@kernel.org \
    --to=johan@kernel.org \
    --cc=andrew.smirnov@gmail.com \
    --cc=gregkh@linuxfoundation.org \
    --cc=jslaby@suse.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-serial@vger.kernel.org \
    --cc=robh@kernel.org \
    --subject='Re: [PATCH 3/4] serdev: make synchronous write helper interruptible' \
    /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

This is a public inbox, see mirroring instructions
on how to clone and mirror all data and code used for this inbox