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V4L/DVB: IR/streamzap: fix usec to nsec conversion

PATCH In review Dan Carpenter 2 participants 2 messages Oct 12, 2010

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Dan Carpenter

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#0 lore raw

PATCH 1/1 V4L/DVB: IR/streamzap: fix usec to nsec conversion

There is an integer overflow here because 0x03000000 * 1000 is too large for 31 bits.

rawir.duration should be in terms of nsecs.
IR_MAX_DURATION and 0x03000000 are already in terms of nsecs. STREAMZAP_TIMEOUT and STREAMZAP_RESOLUTION are 255 and 256 respectively and are in terms of usecs.

The original code had a deadline of 1.005 seconds and the new code has a deadline of .065 seconds.

Signed-off-by Dan Carpenter <[email protected]>
drivers/media/IR/streamzap.c +2 -2
index 2cf57e6..d5d3cee 100644
@@ -221,7 +221,7 @@ static void streamzap_callback(struct urb *urb)
 	struct streamzap_ir *sz;
 	unsigned int i;
 	int len;
-	static int timeout = (((STREAMZAP_TIMEOUT * STREAMZAP_RESOLUTION) &
+	static int timeout = (((STREAMZAP_TIMEOUT * STREAMZAP_RESOLUTION * 1000) &
 				IR_MAX_DURATION) | 0x03000000);
 
 	if (!urb)

@@ -273,7 +273,7 @@ static void streamzap_callback(struct urb *urb)
 				struct ir_raw_event rawir;
 
 				rawir.pulse = false;
-				rawir.duration = timeout * 1000;
+				rawir.duration = timeout;
 				sz->idle = true;
 				if (sz->timeout_enabled)
 					sz_push(sz, rawir);
Acked-by on v1 1/1
#1 lore raw
Quoted 8 lines · Dan Carpenter

There is an integer overflow here because 0x03000000 * 1000 is too large for 31 bits.

rawir.duration should be in terms of nsecs.
IR_MAX_DURATION and 0x03000000 are already in terms of nsecs. STREAMZAP_TIMEOUT and STREAMZAP_RESOLUTION are 255 and 256 respectively and are in terms of usecs.

Quoted 4 lines

The original code had a deadline of 1.005 seconds and the new code has a deadline of .065 seconds.

Signed-off-by Dan Carpenter <[email protected]>

Nice catch, fix looks good.

Acked-by Jarod Wilson <[email protected]>
Signature · 2 lines
Jarod Wilson
[email protected]