summaryrefslogtreecommitdiffstats
path: root/drivers/phy
diff options
context:
space:
mode:
authorM. Vefa Bicakci <m.v.b@runbox.com>2020-09-22 14:07:03 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2020-09-25 16:53:02 +0200
commit3fce39601a1a34d940cf62858ee01ed9dac5d459 (patch)
tree799585e2e5526d484eda5a29d9883fcab64ed33f /drivers/phy
parent4df30e7603432704380b12fe40a604ee7f66746d (diff)
downloadlinux-3fce39601a1a34d940cf62858ee01ed9dac5d459.tar.gz
linux-3fce39601a1a34d940cf62858ee01ed9dac5d459.tar.bz2
linux-3fce39601a1a34d940cf62858ee01ed9dac5d459.zip
usbcore/driver: Accommodate usbip
Commit 88b7381a939d ("USB: Select better matching USB drivers when available") inadvertently broke usbip functionality. The commit in question allows USB device drivers to be explicitly matched with USB devices via the use of driver-provided identifier tables and match functions, which is useful for a specialised device driver to be chosen for a device that can also be handled by another, more generic, device driver. Prior, the USB device section of usb_device_match() had an unconditional "return 1" statement, which allowed user-space to bind USB devices to the usbip_host device driver, if desired. However, the aforementioned commit changed the default/fallback return value to zero. This breaks device drivers such as usbip_host, so this commit restores the legacy behaviour, but only if a device driver does not have an id_table and a match() function. In addition, if usb_device_match is called for a device driver and device pair where the device does not match the id_table of the device driver in question, then the device driver will be disqualified for the device. This allows avoiding the default case of "return 1", which prevents undesirable probe() calls to a driver even though its id_table did not match the device. Finally, this commit changes the specialised-driver-to-generic-driver transition code so that when a device driver returns -ENODEV, a more generic device driver is only considered if the current device driver does not have an id_table and a match() function. This ensures that "generic" drivers such as usbip_host will not be considered specialised device drivers and will not cause the device to be locked in to the generic device driver, when a more specialised device driver could be tried. All of these changes restore usbip functionality without regressions, ensure that the specialised/generic device driver selection logic works as expected with the usb and apple-mfi-fastcharge drivers, and do not negatively affect the use of devices provided by dummy_hcd. Fixes: 88b7381a939d ("USB: Select better matching USB drivers when available") Cc: <stable@vger.kernel.org> # 5.8 Cc: Bastien Nocera <hadess@hadess.net> Cc: Valentina Manea <valentina.manea.m@gmail.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: <syzkaller@googlegroups.com> Tested-by: Andrey Konovalov <andreyknvl@google.com> Acked-by: Shuah Khan <skhan@linuxfoundation.org> Signed-off-by: M. Vefa Bicakci <m.v.b@runbox.com> Link: https://lore.kernel.org/r/20200922110703.720960-5-m.v.b@runbox.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/phy')
0 files changed, 0 insertions, 0 deletions