From 06a962fa7f9bf068eb1238d7aa20453b9e11a9fd Mon Sep 17 00:00:00 2001 From: Julius Werner Date: Fri, 31 May 2013 18:34:52 -0700 Subject: [PATCH] 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 Signed-off-by: Dongjin Kim Acked-by: Olof Johansson Signed-off-by: Greg Kroah-Hartman --- drivers/usb/misc/usb3503.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/drivers/usb/misc/usb3503.c b/drivers/usb/misc/usb3503.c index a56299dbfaf4..c3578393ddef 100644 --- 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; } -- 2.20.1