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-rw-r--r--drivers/media/usb/em28xx/em28xx.h17
1 files changed, 15 insertions, 2 deletions
diff --git a/drivers/media/usb/em28xx/em28xx.h b/drivers/media/usb/em28xx/em28xx.h
index b0aa849..efdf386 100644
--- a/drivers/media/usb/em28xx/em28xx.h
+++ b/drivers/media/usb/em28xx/em28xx.h
@@ -183,8 +183,21 @@
#define EM28XX_INTERLACED_DEFAULT 1
-/* time in msecs to wait for i2c writes to finish */
-#define EM2800_I2C_XFER_TIMEOUT 20
+/*
+ * Time in msecs to wait for i2c xfers to finish.
+ * 35ms is the maximum time a SMBUS device could wait when
+ * clock stretching is used. As the transfer itself will take
+ * some time to happen, set it to 35 ms.
+ *
+ * Ok, I2C doesn't specify any limit. So, eventually, we may need
+ * to increase this timeout.
+ *
+ * FIXME: this assumes that an I2C message is not longer than 1ms.
+ * This is actually dependent on the I2C bus speed, although most
+ * devices use a 100kHz clock. So, this assumtion is true most of
+ * the time.
+ */
+#define EM28XX_I2C_XFER_TIMEOUT 36
/* time in msecs to wait for AC97 xfers to finish */
#define EM28XX_AC97_XFER_TIMEOUT 100
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