3.14-stable review patch. If anyone has any objections, please let me know.
------------------ From: Daniel Mack <[email protected]> commit a31a942a148e0083ce560ffeb54fb60e06ab7201 upstream. Tests have shown that when a power-up transition is followed by other PHY operations too quickly, the USB port appears dead. Waiting 1ms fixes this problem. Signed-off-by: Daniel Mack <[email protected]> Signed-off-by: Felipe Balbi <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- drivers/usb/phy/phy-am335x-control.c | 9 +++++++++ 1 file changed, 9 insertions(+) --- a/drivers/usb/phy/phy-am335x-control.c +++ b/drivers/usb/phy/phy-am335x-control.c @@ -3,6 +3,7 @@ #include <linux/err.h> #include <linux/of.h> #include <linux/io.h> +#include <linux/delay.h> #include "am35x-phy-control.h" struct am335x_control_usb { @@ -86,6 +87,14 @@ static void am335x_phy_power(struct phy_ } writel(val, usb_ctrl->phy_reg + reg); + + /* + * Give the PHY ~1ms to complete the power up operation. + * Tests have shown unstable behaviour if other USB PHY related + * registers are written too shortly after such a transition. + */ + if (on) + mdelay(1); } static const struct phy_control ctrl_am335x = { -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
