usb: misc: usb3503: Remove 100ms sleep on reset, conform to data sheet

The usb3503 driver sleeps a flat 100ms when resetting the chip, with a comment about waiting for the reference clock. This seems to be a board-specific detail that should not hold up boot across all platforms. This patch reduces the sleep to the 4ms initialization delay that the chip itself actually requires (as per its data sheet). If certain boards require more time to set up the reference clock, they should change this through local patches or add a proper, configurable synchronization mechanism. Signed-off-by: Julius Werner <[email protected]> Signed-off-by: Dongjin Kim <[email protected]> Acked-by: Olof Johansson <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
iegor · Jun 3, 2013 · 06a962f · 06a962f
1 parent ccf92c9
commit 06a962f
Showing 1 changed file with 2 additions and 4 deletions.
diff --git a/drivers/usb/misc/usb3503.c b/drivers/usb/misc/usb3503.c
@@ -105,11 +105,9 @@ static int usb3503_reset(int gpio_reset, int state)
 	if (gpio_is_valid(gpio_reset))
 		gpio_set_value(gpio_reset, state);
 
-	/* Wait RefClk when RESET_N is released, otherwise Hub will
-	 * not transition to Hub Communication Stage.
-	 */
+	/* Wait T_HUBINIT == 4ms for hub logic to stabilize */
 	if (state)
-		msleep(100);
+		usleep_range(4000, 10000);
 
 	return 0;
 }