[v2] usb: warm-reset ports on hub resume, if requested

Commit Message

Jan-Marek Glogowski Jan. 16, 2019, 4:06 p.m. UTC

On plug-in of my USB-C device, its USB_SS_PORT_LS_SS_INACTIVE
link state bit is set. Greping all the kernel for this bit shows
that the port status requests a warm-reset this way.

This just happens, if its the only device on that hub and the
hub resumes, so we don't call port_event, which would otherwise
warm-reset ports. The device works ok without this patch, if
there is already any other device connected to the hub.

Signed-off-by: Jan-Marek Glogowski <[e-mail]>
---
 drivers/usb/core/hub.c | 21 +++++++++++++++------
 1 file changed, 15 insertions(+), 6 deletions(-)

Comments

Greg Kroah-Hartman Jan. 16, 2019, 4:43 p.m. UTC | #1

On Wed, Jan 16, 2019 at 05:06:33PM +0100, Jan-Marek Glogowski wrote:
> On plug-in of my USB-C device, its USB_SS_PORT_LS_SS_INACTIVE
> link state bit is set. Greping all the kernel for this bit shows
> that the port status requests a warm-reset this way.
> 
> This just happens, if its the only device on that hub and the
> hub resumes, so we don't call port_event, which would otherwise
> warm-reset ports. The device works ok without this patch, if
> there is already any other device connected to the hub.
> 
> Signed-off-by: Jan-Marek Glogowski <[e-mail]>
> ---
>  drivers/usb/core/hub.c | 21 +++++++++++++++------
>  1 file changed, 15 insertions(+), 6 deletions(-)

What changed from v1?  Always put that below the --- line, as the
documentation asks you to do.

v3 please?

thanks,

greg k-h

Patch

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 1d1e61e..e0cc740 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -108,6 +108,16 @@  EXPORT_SYMBOL_GPL(ehci_cf_port_reset_rwsem);
 static void hub_release(struct kref *kref);
 static int usb_reset_and_verify_device(struct usb_device *udev);
 static int hub_port_disable(struct usb_hub *hub, int port1, int set_state);
+static bool hub_port_warm_reset_required(struct usb_hub *hub, int port1,
+		u16 portstatus);
+static int hub_port_reset(struct usb_hub *hub, int port1,
+			struct usb_device *udev, unsigned int delay, bool warm);
+
+#define HUB_ROOT_RESET_TIME	60	/* times are in msec */
+#define HUB_SHORT_RESET_TIME	10
+#define HUB_BH_RESET_TIME	50
+#define HUB_LONG_RESET_TIME	200
+#define HUB_RESET_TIMEOUT	800
 
 static inline char *portspeed(struct usb_hub *hub, int portstatus)
 {
@@ -1122,6 +1132,11 @@  static void hub_activate(struct usb_hub *hub, enum hub_activation_type type)
 						USB_SS_PORT_LS_POLLING))
 			need_debounce_delay = true;
 
+		if (type == HUB_RESUME &&
+		    hub_port_warm_reset_required(hub, port1, portstatus))
+			hub_port_reset(hub, port1, udev,
+					HUB_BH_RESET_TIME, true);
+
 		/* Clear status-change flags; we'll debounce later */
 		if (portchange & USB_PORT_STAT_C_CONNECTION) {
 			need_debounce_delay = true;
@@ -2653,12 +2668,6 @@  static unsigned hub_is_wusb(struct usb_hub *hub)
 #define SET_CONFIG_TRIES	(2 * (use_both_schemes + 1))
 #define USE_NEW_SCHEME(i, scheme)	((i) / 2 == (int)scheme)
 
-#define HUB_ROOT_RESET_TIME	60	/* times are in msec */
-#define HUB_SHORT_RESET_TIME	10
-#define HUB_BH_RESET_TIME	50
-#define HUB_LONG_RESET_TIME	200
-#define HUB_RESET_TIMEOUT	800
-
 /*
  * "New scheme" enumeration causes an extra state transition to be
  * exposed to an xhci host and causes USB3 devices to receive control