[PATCH 1/1] rc: Fix input deadlock and transmit error in redrat3 driver

[PATCH 1/1] rc: Fix input deadlock and transmit error in redrat3 driver

[Andrew Vincer]

Fixed submit urb logic so hardware doesn't hang trying to transmit
signal data

Removed unneeded enable/disable detector commands in
redrat3_transmit_ir (the hardware does this anyway) and converted
arguments to unsigned as per 5588dc2

Signed-off-by: Andrew Vincer <andrew@redrat.co.uk>
---
 drivers/media/rc/redrat3.c |   52 +++++++++++++++----------------------------
 1 files changed, 18 insertions(+), 34 deletions(-)

diff --git a/drivers/media/rc/redrat3.c b/drivers/media/rc/redrat3.c
index 61287fc..9bff23c 100644
--- a/drivers/media/rc/redrat3.c
+++ b/drivers/media/rc/redrat3.c
@@ -286,12 +286,6 @@ static void redrat3_issue_async(struct redrat3_dev *rr3)
 
 	rr3_ftr(rr3->dev, "Entering %s\n", __func__);
 
-	if (!rr3->det_enabled) {
-		dev_warn(rr3->dev, "not issuing async read, "
-			 "detector not enabled\n");
-		return;
-	}
-
 	memset(rr3->bulk_in_buf, 0, rr3->ep_in->wMaxPacketSize);
 	res = usb_submit_urb(rr3->read_urb, GFP_ATOMIC);
 	if (res)
@@ -827,6 +821,7 @@ out:
 static void redrat3_handle_async(struct urb *urb, struct pt_regs *regs)
 {
 	struct redrat3_dev *rr3;
+	int ret;
 
 	if (!urb)
 		return;
@@ -840,15 +835,13 @@ static void redrat3_handle_async(struct urb *urb, struct pt_regs *regs)
 
 	rr3_ftr(rr3->dev, "Entering %s\n", __func__);
 
-	if (!rr3->det_enabled) {
-		rr3_dbg(rr3->dev, "received a read callback but detector "
-			"disabled - ignoring\n");
-		return;
-	}
-
 	switch (urb->status) {
 	case 0:
-		redrat3_get_ir_data(rr3, urb->actual_length);
+		ret = redrat3_get_ir_data(rr3, urb->actual_length);
+		if (!ret) {
+			/* no error, prepare to read more */
+			redrat3_issue_async(rr3);
+		}
 		break;
 
 	case -ECONNRESET:
@@ -865,11 +858,6 @@ static void redrat3_handle_async(struct urb *urb, struct pt_regs *regs)
 		rr3->pkttype = 0;
 		break;
 	}
-
-	if (!rr3->transmitting)
-		redrat3_issue_async(rr3);
-	else
-		rr3_dbg(rr3->dev, "IR transmit in progress\n");
 }
 
 static void redrat3_write_bulk_callback(struct urb *urb, struct pt_regs *regs)
@@ -896,21 +884,24 @@ static u16 mod_freq_to_val(unsigned int mod_freq)
 	return (u16)(65536 - (mult / mod_freq));
 }
 
-static int redrat3_set_tx_carrier(struct rc_dev *dev, u32 carrier)
+static int redrat3_set_tx_carrier(struct rc_dev *rcdev, u32 carrier)
 {
-	struct redrat3_dev *rr3 = dev->priv;
+	struct redrat3_dev *rr3 = rcdev->priv;
+	struct device *dev = rr3->dev;
 
+	rr3_dbg(dev, "Setting modulation frequency to %u", carrier);
 	rr3->carrier = carrier;
 
 	return carrier;
 }
 
-static int redrat3_transmit_ir(struct rc_dev *rcdev, int *txbuf, u32 n)
+static int redrat3_transmit_ir(struct rc_dev *rcdev, unsigned *txbuf,
+				unsigned count)
 {
 	struct redrat3_dev *rr3 = rcdev->priv;
 	struct device *dev = rr3->dev;
 	struct redrat3_signal_header header;
-	int i, j, count, ret, ret_len, offset;
+	int i, j, ret, ret_len, offset;
 	int lencheck, cur_sample_len, pipe;
 	char *buffer = NULL, *sigdata = NULL;
 	int *sample_lens = NULL;
@@ -928,20 +919,13 @@ static int redrat3_transmit_ir(struct rc_dev *rcdev, int *txbuf, u32 n)
 		return -EAGAIN;
 	}
 
-	count = n / sizeof(int);
 	if (count > (RR3_DRIVER_MAXLENS * 2))
 		return -EINVAL;
 
+	/* rr3 will disable rc detector on transmit */
+	rr3->det_enabled = false;
 	rr3->transmitting = true;
 
-	redrat3_disable_detector(rr3);
-
-	if (rr3->det_enabled) {
-		dev_err(dev, "%s: cannot tx while rx is enabled\n", __func__);
-		ret = -EIO;
-		goto out;
-	}
-
 	sample_lens = kzalloc(sizeof(int) * RR3_DRIVER_MAXLENS, GFP_KERNEL);
 	if (!sample_lens) {
 		ret = -ENOMEM;
@@ -1055,7 +1039,7 @@ static int redrat3_transmit_ir(struct rc_dev *rcdev, int *txbuf, u32 n)
 	if (ret < 0)
 		dev_err(dev, "Error: control msg send failed, rc %d\n", ret);
 	else
-		ret = n;
+		ret = count;
 
 out:
 	kfree(sample_lens);
@@ -1063,8 +1047,8 @@ out:
 	kfree(sigdata);
 
 	rr3->transmitting = false;
-
-	redrat3_enable_detector(rr3);
+	/* rr3 re-enables rc detector because it was enabled before */
+	rr3->det_enabled = true;
 
 	return ret;
 }
-- 
1.7.1

Re: [PATCH 1/1] rc: Fix input deadlock and transmit error in redrat3 driver

[Dan Carpenter]

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On Tue, Nov 08, 2011 at 04:43:45PM +0000, Andrew Vincer wrote:
> Fixed submit urb logic so hardware doesn't hang trying to transmit
> signal data
> 
> Removed unneeded enable/disable detector commands in
> redrat3_transmit_ir (the hardware does this anyway) and converted
> arguments to unsigned as per 5588dc2
> 

This would be easier to review it you put the changes to enable and
disable into one patch and the changes so that we now measure the
buffer length in bytes instead of ints into a second patch.

regards,
dan carpenter


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