public inbox for linux-media@vger.kernel.org
 help / color / mirror / Atom feed
From: Andy Walls <awalls@md.metrocast.net>
To: linux-media@vger.kernel.org
Subject: [PATCH 07/13] lirc_zilog: Remove unneeded rx->buf_lock
Date: Thu, 17 Feb 2011 20:17:40 -0500	[thread overview]
Message-ID: <1297991860.9399.23.camel@localhost> (raw)
In-Reply-To: <1297991502.9399.16.camel@localhost>

 
Remove the rx->buf_lock that protected the rx->buf lirc_buffer.  The
underlying operations on the objects within the lirc_buffer are already
protected by spinlocks, or the objects are constant (e.g. chunk_size).

Signed-off-by: Andy Walls <awalls@md.metrocast.net>
---
 drivers/staging/lirc/lirc_zilog.c |   23 +++++++++--------------
 1 files changed, 9 insertions(+), 14 deletions(-)

diff --git a/drivers/staging/lirc/lirc_zilog.c b/drivers/staging/lirc/lirc_zilog.c
index dfa6a42..0f2fa58 100644
--- a/drivers/staging/lirc/lirc_zilog.c
+++ b/drivers/staging/lirc/lirc_zilog.c
@@ -67,9 +67,8 @@ struct IR_rx {
 	/* RX device */
 	struct i2c_client *c;
 
-	/* RX device buffer & lock */
+	/* RX device buffer */
 	struct lirc_buffer buf;
-	struct mutex buf_lock;
 
 	/* RX polling thread data */
 	struct task_struct *task;
@@ -718,18 +717,15 @@ static ssize_t read(struct file *filep, char *outbuf, size_t n, loff_t *ppos)
 	struct IR *ir = filep->private_data;
 	struct IR_rx *rx = ir->rx;
 	int ret = 0, written = 0;
+	unsigned int m;
 	DECLARE_WAITQUEUE(wait, current);
 
 	dprintk("read called\n");
 	if (rx == NULL)
 		return -ENODEV;
 
-	if (mutex_lock_interruptible(&rx->buf_lock))
-		return -ERESTARTSYS;
-
 	if (n % rx->buf.chunk_size) {
 		dprintk("read result = -EINVAL\n");
-		mutex_unlock(&rx->buf_lock);
 		return -EINVAL;
 	}
 
@@ -767,19 +763,19 @@ static ssize_t read(struct file *filep, char *outbuf, size_t n, loff_t *ppos)
 			set_current_state(TASK_INTERRUPTIBLE);
 		} else {
 			unsigned char buf[rx->buf.chunk_size];
-			lirc_buffer_read(&rx->buf, buf);
-			ret = copy_to_user((void *)outbuf+written, buf,
-					   rx->buf.chunk_size);
-			written += rx->buf.chunk_size;
+			m = lirc_buffer_read(&rx->buf, buf);
+			if (m == rx->buf.chunk_size) {
+				ret = copy_to_user((void *)outbuf+written, buf,
+						   rx->buf.chunk_size);
+				written += rx->buf.chunk_size;
+			}
 		}
 	}
 
 	remove_wait_queue(&rx->buf.wait_poll, &wait);
 	set_current_state(TASK_RUNNING);
-	mutex_unlock(&rx->buf_lock);
 
-	dprintk("read result = %s (%d)\n",
-		ret ? "-EFAULT" : "OK", ret);
+	dprintk("read result = %d (%s)\n", ret, ret ? "Error" : "OK");
 
 	return ret ? ret : written;
 }
@@ -1327,7 +1323,6 @@ static int ir_probe(struct i2c_client *client, const struct i2c_device_id *id)
 		if (ret)
 			goto out_free_xx;
 
-		mutex_init(&ir->rx->buf_lock);
 		ir->rx->c = client;
 		ir->rx->hdpvr_data_fmt =
 			       (id->driver_data & ID_FLAG_HDPVR) ? true : false;
-- 
1.7.2.1




  parent reply	other threads:[~2011-02-18  1:17 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-02-18  1:11 [PATCH 0/13] lirc_zilog: Ref-counting and locking cleanup Andy Walls
2011-02-18  1:12 ` [PATCH 01/13] lirc_zilog: Restore checks for existence of the IR_tx object Andy Walls
2011-02-18  1:13 ` [PATCH 02/13] lirc_zilog: Remove broken, ineffective reference counting Andy Walls
2011-02-18  1:14 ` [PATCH 03/13] lirc_zilog: Convert ir_device instance array to a linked list Andy Walls
2011-02-18  1:15 ` [PATCH 04/13] lirc_zilog: Convert the instance open count to an atomic_t Andy Walls
2011-02-18  1:15 ` [PATCH 05/13] lirc_zilog: Use kernel standard methods for marking device non-seekable Andy Walls
2011-02-18  1:16 ` [PATCH 06/13] lirc_zilog: Don't acquire the rx->buf_lock in the poll() function Andy Walls
2011-02-18  1:17 ` Andy Walls [this message]
2011-02-18  1:18 ` [PATCH 08/13] lirc_zilog: Always allocate a Rx lirc_buffer object Andy Walls
2011-02-18  1:19 ` [PATCH 09/13] lirc_zilog: Move constants from ir_probe() into the lirc_driver template Andy Walls
2011-02-18  1:20 ` [PATCH 10/13] lirc_zilog: Add ref counting of struct IR, IR_tx, and IR_rx Andy Walls
2011-02-18  1:20 ` [PATCH 11/13] lirc_zilog: Add locking of the i2c_clients when in use Andy Walls
2011-02-18  1:21 ` [PATCH 12/13] lirc_zilog: Fix somewhat confusing information messages in ir_probe() Andy Walls
2011-02-18  1:22 ` [PATCH 13/13] lirc_zilog: Update TODO list based on work completed and revised plans Andy Walls
2011-03-06  4:00 ` [PATCH 0/13] lirc_zilog: Ref-counting and locking cleanup Jarod Wilson

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=1297991860.9399.23.camel@localhost \
    --to=awalls@md.metrocast.net \
    --cc=linux-media@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