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authorJames P Michels III <james.p.michels@gmail.com>2014-07-27 13:28:04 -0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-08-01 15:47:05 -0700
commitcd83ce9e6195aa3ea15ab4db92892802c20df5d0 (patch)
tree8b75990711e5ce8d060f2e7e236c32ca68e17a14 /include/linux/usb/quirks.h
parent4bdcde358b4bda74e356841d351945ca3f2245dd (diff)
usb-core bInterval quirk
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>
Diffstat (limited to 'include/linux/usb/quirks.h')
-rw-r--r--include/linux/usb/quirks.h11
1 files changed, 11 insertions, 0 deletions
diff --git a/include/linux/usb/quirks.h b/include/linux/usb/quirks.h
index 52f944dfe2fd..55a17b188daa 100644
--- 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 */