diff options
| author |   Nicolas Boichat <drinkcat@chromium.org> | 2018-05-28 14:32:18 +0800 |
|---|---|---|
| committer |   Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-05-31 12:48:17 +0200 |
| commit | 25244227158e1502062041365a439a54cb8fe673 (patch) | |
| tree | 87af664545c88bc045cd1598c79caad305d77178 /drivers/usb/core/hub.c | |
| parent | usb: xhci: tegra: Fix runtime PM support (diff) | |
| download | linux-dev-25244227158e1502062041365a439a54cb8fe673.tar.xz linux-dev-25244227158e1502062041365a439a54cb8fe673.zip | |
usb: hub: Per-port setting to use old enumeration scheme
The "old" enumeration scheme is considerably faster (it takes
~244ms instead of ~356ms to get the descriptor).
It is currently only possible to use the old scheme globally
(/sys/module/usbcore/parameters/old_scheme_first), which is not
desirable as the new scheme was introduced to increase compatibility
with more devices.
However, in our case, we care about time-to-active for a specific
USB device (which we make the firmware for), on a specific port
(that is pogo-pin based: not a standard USB port). This new
sysfs option makes it possible to use the old scheme on a single
port only.
Signed-off-by: Nicolas Boichat <drinkcat@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb/core/hub.c')
| -rw-r--r-- | drivers/usb/core/hub.c | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index c2d993d3816f..f900f66a6285 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -2636,7 +2636,7 @@ static unsigned hub_is_wusb(struct usb_hub *hub) #define SET_ADDRESS_TRIES 2 #define GET_DESCRIPTOR_TRIES 2 #define SET_CONFIG_TRIES (2 * (use_both_schemes + 1)) -#define USE_NEW_SCHEME(i) ((i) / 2 == (int)old_scheme_first) +#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 @@ -2651,12 +2651,16 @@ static unsigned hub_is_wusb(struct usb_hub *hub) * enumeration failures, so disable this enumeration scheme for USB3 * devices. */ -static bool use_new_scheme(struct usb_device *udev, int retry) +static bool use_new_scheme(struct usb_device *udev, int retry, + struct usb_port *port_dev) { + int old_scheme_first_port = + port_dev->quirks & USB_PORT_QUIRK_OLD_SCHEME; + if (udev->speed >= USB_SPEED_SUPER) return false; - return USE_NEW_SCHEME(retry); + return USE_NEW_SCHEME(retry, old_scheme_first_port || old_scheme_first); } /* Is a USB 3.0 port in the Inactive or Compliance Mode state? @@ -4392,6 +4396,7 @@ hub_port_init(struct usb_hub *hub, struct usb_device *udev, int port1, { struct usb_device *hdev = hub->hdev; struct usb_hcd *hcd = bus_to_hcd(hdev->bus); + struct usb_port *port_dev = hub->ports[port1 - 1]; int retries, operations, retval, i; unsigned delay = HUB_SHORT_RESET_TIME; enum usb_device_speed oldspeed = udev->speed; @@ -4513,7 +4518,7 @@ hub_port_init(struct usb_hub *hub, struct usb_device *udev, int port1, for (retries = 0; retries < GET_DESCRIPTOR_TRIES; (++retries, msleep(100))) { bool did_new_scheme = false; - if (use_new_scheme(udev, retry_counter)) { + if (use_new_scheme(udev, retry_counter, port_dev)) { struct usb_device_descriptor *buf; int r = 0; |