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| author | Alan Stern <stern@rowland.harvard.edu> | 2015-12-10 15:27:21 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-01-22 20:34:52 -0800 |
| commit | 4180d57beb422ce28d563fee25b5fc45bb9c3186 (patch) | |
| tree | 60e67d3fd9b20332669bccfd65af7c3bc97e7731 /include | |
| parent | 367f16c8077c8951d9724fec652f8b218931bd61 (diff) | |
| download | lwn-4180d57beb422ce28d563fee25b5fc45bb9c3186.tar.gz lwn-4180d57beb422ce28d563fee25b5fc45bb9c3186.zip | |
USB: add quirk for devices with broken LPM
commit ad87e03213b552a5c33d5e1e7a19a73768397010 upstream.
Some USB device / host controller combinations seem to have problems
with Link Power Management. For example, Steinar found that his xHCI
controller wouldn't handle bandwidth calculations correctly for two
video cards simultaneously when LPM was enabled, even though the bus
had plenty of bandwidth available.
This patch introduces a new quirk flag for devices that should remain
disabled for LPM, and creates quirk entries for Steinar's devices.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Reported-by: Steinar H. Gunderson <sgunderson@bigfoot.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/usb/quirks.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/include/linux/usb/quirks.h b/include/linux/usb/quirks.h index 8b96ae2a38fe..5ef39160bd47 100644 --- a/include/linux/usb/quirks.h +++ b/include/linux/usb/quirks.h @@ -36,4 +36,7 @@ /* device can't handle device_qualifier descriptor requests */ #define USB_QUIRK_DEVICE_QUALIFIER 0x00000100 +/* device can't handle Link Power Management */ +#define USB_QUIRK_NO_LPM BIT(10) + #endif /* __LINUX_USB_QUIRKS_H */ |