From 9684352036a63e03f9524be7458dd3a9e512c4bf Mon Sep 17 00:00:00 2001 From: Jonathan Bakker Date: Sat, 25 Apr 2020 10:36:33 -0700 Subject: [PATCH] phy: samsung: s5pv210-usb2: Add delay after reset The USB phy takes some time to reset, so make sure we give it to it. The delay length was taken from the 4x12 phy driver. This manifested in issues with the DWC2 driver since commit d91d4a4a8069 ("usb: dwc2: Make dwc2_readl/writel functions endianness-agnostic.") where the endianness check would read the DWC ID as 0 due to the phy still resetting, resulting in the wrong endian mode being chosen. Signed-off-by: Jonathan Bakker Link: https://lore.kernel.org/r/BN6PR04MB06605D52502816E500683553A3D10@BN6PR04MB0660.namprd04.prod.outlook.com Signed-off-by: Kishon Vijay Abraham I --- drivers/phy/samsung/phy-s5pv210-usb2.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/phy/samsung/phy-s5pv210-usb2.c b/drivers/phy/samsung/phy-s5pv210-usb2.c index 56a5083fe6f94..32be62e498047 100644 --- a/drivers/phy/samsung/phy-s5pv210-usb2.c +++ b/drivers/phy/samsung/phy-s5pv210-usb2.c @@ -139,6 +139,10 @@ static void s5pv210_phy_pwr(struct samsung_usb2_phy_instance *inst, bool on) udelay(10); rst &= ~rstbits; writel(rst, drv->reg_phy + S5PV210_UPHYRST); + /* The following delay is necessary for the reset sequence to be + * completed + */ + udelay(80); } else { pwr = readl(drv->reg_phy + S5PV210_UPHYPWR); pwr |= phypwr; -- 2.39.5