| Message ID | 20181003051822.4011-1-kai.heng.feng@canonical.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | usb: core: Check portchange C_PORT_RESET after resetting | expand |
On Wed, 3 Oct 2018, Kai-Heng Feng wrote: > Based on USB2.0 Spec Section 11.24.2.7.2.5: > > "This bit is set when the port transitions from the Resetting state (or, > if present, the Speed_eval state) to the Enabled state." > > Also Section 11.24.2.13: > > "Setting the reset feature PORT_RESET causes the hub to signal reset on > that port. When the reset signaling is complete, the hub sets the > C_PORT_RESET status change and immediately enables the port." > > So let's also check C_PORT_RESET for reset completion. > > Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com> > --- > drivers/usb/core/hub.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c > index 7801bb30bdba..d96058372280 100644 > --- a/drivers/usb/core/hub.c > +++ b/drivers/usb/core/hub.c > @@ -2721,7 +2721,8 @@ static int hub_port_wait_reset(struct usb_hub *hub, int port1, > * so also wait for the connection to be re-established. > */ > if (!(portstatus & USB_PORT_STAT_RESET) && > - (portstatus & USB_PORT_STAT_CONNECTION)) > + (portstatus & USB_PORT_STAT_CONNECTION) && > + (portchange & USB_PORT_STAT_C_RESET)) > break; > > /* switch to the long delay after two short delay failures */ What is the purpose of this patch? Does it fix a problem? Alan Stern
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index 7801bb30bdba..d96058372280 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -2721,7 +2721,8 @@ static int hub_port_wait_reset(struct usb_hub *hub, int port1, * so also wait for the connection to be re-established. */ if (!(portstatus & USB_PORT_STAT_RESET) && - (portstatus & USB_PORT_STAT_CONNECTION)) + (portstatus & USB_PORT_STAT_CONNECTION) && + (portchange & USB_PORT_STAT_C_RESET)) break; /* switch to the long delay after two short delay failures */
Based on USB2.0 Spec Section 11.24.2.7.2.5: "This bit is set when the port transitions from the Resetting state (or, if present, the Speed_eval state) to the Enabled state." Also Section 11.24.2.13: "Setting the reset feature PORT_RESET causes the hub to signal reset on that port. When the reset signaling is complete, the hub sets the C_PORT_RESET status change and immediately enables the port." So let's also check C_PORT_RESET for reset completion. Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com> --- drivers/usb/core/hub.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)