From: Fabio Estevam <fabio.este...@nxp.com>

On a mx28 board with a USB hub the following error is observed:

hub 1-1:1.0: USB hub found
hub 1-1:1.0: 2 ports detected
usb 1-1: USB disconnect, device number 2
usb usb1-port1: cannot reset (err = -32)
usb usb1-port1: cannot reset (err = -32)
usb usb1-port1: cannot reset (err = -32)
usb usb1-port1: cannot reset (err = -32)
usb usb1-port1: cannot reset (err = -32)
usb usb1-port1: Cannot enable. Maybe the USB cable is bad?

,which is caused by a problem described by the MXS_PHY_ABNORMAL_IN_SUSPEND
flag.

As we currently do not have a proper implementation for this issue, one
possible workaround is to pass "usbcore.autosuspend=-1" in the kernel
command line, so add this suggestion into the MXS_PHY_ABNORMAL_IN_SUSPEND
flag description.

Signed-off-by: Fabio Estevam <fabio.este...@nxp.com>
Acked-by: Peter Chen <peter.c...@nxp.com>
---
 drivers/usb/phy/phy-mxs-usb.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/usb/phy/phy-mxs-usb.c b/drivers/usb/phy/phy-mxs-usb.c
index 00bfea0..be46ab3 100644
--- a/drivers/usb/phy/phy-mxs-usb.c
+++ b/drivers/usb/phy/phy-mxs-usb.c
@@ -98,6 +98,10 @@
  * The PHY will be in messy if there is a wakeup after putting
  * bus to suspend (set portsc.suspendM) but before setting PHY to low
  * power mode (set portsc.phcd).
+ *
+ * To work around this problem on mx23/mx28 user should pass
+ * "usbcore.autosuspend=-1" in the kernel command line for now, as
+ * we do not have a proper fix for this flag in the kernel yet.
  */
 #define MXS_PHY_ABNORMAL_IN_SUSPEND            BIT(1)
 
-- 
1.9.1

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