Since the controller on R-Car Gen3 doesn't have any status registers to detect initialization (LPSTS.SUSPM = 1) and the initialization needs up to 45 usec, this patch adds wait after the initialization. Otherwise, writing other registers (e.g. INTENB0) will fail. Fixes: de18757e272d ("usb: renesas_usbhs: add R-Car Gen3 power control") Cc: <stable@xxxxxxxxxxxxxxx> # v4.6+ Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx> --- This patch is based on the latest Felipe's usb.git / testing/fixes branch (commit id = a1aa8cf6471b17c0fa7132ea5eeef0ae07ca07cd). drivers/usb/renesas_usbhs/rcar3.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/usb/renesas_usbhs/rcar3.c b/drivers/usb/renesas_usbhs/rcar3.c index 1d70add..d544b33 100644 --- a/drivers/usb/renesas_usbhs/rcar3.c +++ b/drivers/usb/renesas_usbhs/rcar3.c @@ -9,6 +9,7 @@ * */ +#include <linux/delay.h> #include <linux/io.h> #include "common.h" #include "rcar3.h" @@ -35,10 +36,13 @@ static int usbhs_rcar3_power_ctrl(struct platform_device *pdev, usbhs_write32(priv, UGCTRL2, UGCTRL2_RESERVED_3 | UGCTRL2_USB0SEL_OTG); - if (enable) + if (enable) { usbhs_bset(priv, LPSTS, LPSTS_SUSPM, LPSTS_SUSPM); - else + /* The controller on R-Car Gen3 needs to wait up to 45 usec */ + udelay(45); + } else { usbhs_bset(priv, LPSTS, LPSTS_SUSPM, 0); + } return 0; } -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html