usb-core bInterval quirk

commit cd83ce9e6195aa3ea15ab4db92892802c20df5d0 upstream.

This patch adds a usb quirk to support devices with interupt endpoints
and bInterval values expressed as microframes. The quirk causes the
parse endpoint function to modify the reported bInterval to a standards
conforming value.

There is currently code in the endpoint parser that checks for
bIntervals that are outside of the valid range (1-16 for USB 2+ high
speed and super speed interupt endpoints). In this case, the code assumes
the bInterval is being reported in 1ms frames. As well, the correction
is only applied if the original bInterval value is out of the 1-16 range.

With this quirk applied to the device, the bInterval will be
accurately adjusted from microframes to an exponent.

Signed-off-by: James P Michels III <james.p.michels@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>

diff --git a/drivers/usb/core/config.c b/drivers/usb/core/config.c
index 65243832519706e1a4e0f89053a6aacc353f84cb..98cb09617b20d158a944516063009b9ac8228663 100644 (file)
--- a/drivers/usb/core/config.c
+++ b/drivers/usb/core/config.c
@@ -201,6 +201,17 @@ static int usb_parse_endpoint(struct device *ddev, int cfgno, int inum,
                        if (n == 0)
                                n = 9;  /* 32 ms = 2^(9-1) uframes */
                        j = 16;
+
+                       /*
+                        * Adjust bInterval for quirked devices.
+                        * This quirk fixes bIntervals reported in
+                        * linear microframes.
+                        */
+                       if (to_usb_device(ddev)->quirks &
+                               USB_QUIRK_LINEAR_UFRAME_INTR_BINTERVAL) {
+                               n = clamp(fls(d->bInterval), i, j);
+                               i = j = n;
+                       }
                        break;
                default:                /* USB_SPEED_FULL or _LOW */
                        /* For low-speed, 10 ms is the official minimum.

diff --git a/drivers/usb/core/quirks.c b/drivers/usb/core/quirks.c
index 31f7ebf5586875e54327761c02beeb5ec0749448..6fd22252273cfa6dd8234c5300a8b2b4146311de 100644 (file)
--- a/drivers/usb/core/quirks.c
+++ b/drivers/usb/core/quirks.c
@@ -147,6 +147,10 @@ static const struct usb_device_id usb_quirk_list[] = {
        /* SKYMEDI USB_DRIVE */
        { USB_DEVICE(0x1516, 0x8628), .driver_info = USB_QUIRK_RESET_RESUME },
 
+       /* Razer - Razer Blade Keyboard */
+       { USB_DEVICE(0x1532, 0x0116), .driver_info =
+                       USB_QUIRK_LINEAR_UFRAME_INTR_BINTERVAL },
+
        /* BUILDWIN Photo Frame */
        { USB_DEVICE(0x1908, 0x1315), .driver_info =
                        USB_QUIRK_HONOR_BNUMINTERFACES },

diff --git a/include/linux/usb/quirks.h b/include/linux/usb/quirks.h
index 52f944dfe2fd68305f1f19a4f08c018e9226595c..55a17b188daa7481a04d7d0da19be56ad654f5b6 100644 (file)
--- a/include/linux/usb/quirks.h
+++ b/include/linux/usb/quirks.h
@@ -30,4 +30,15 @@
    descriptor */
 #define USB_QUIRK_DELAY_INIT           0x00000040
 
+/*
+ * For high speed and super speed interupt endpoints, the USB 2.0 and
+ * USB 3.0 spec require the interval in microframes
+ * (1 microframe = 125 microseconds) to be calculated as
+ * interval = 2 ^ (bInterval-1).
+ *
+ * Devices with this quirk report their bInterval as the result of this
+ * calculation instead of the exponent variable used in the calculation.
+ */
+#define USB_QUIRK_LINEAR_UFRAME_INTR_BINTERVAL 0x00000080
+
 #endif /* __LINUX_USB_QUIRKS_H */