]> git.proxmox.com Git - mirror_ubuntu-kernels.git/commit
usb: musb: fix remote wakeup racing with suspend
authorDaniel Glöckner <dg@emlix.com>
Mon, 14 May 2018 14:40:05 +0000 (09:40 -0500)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Mon, 14 May 2018 15:04:06 +0000 (17:04 +0200)
commitebc3dd688cd988754a304147753b13e58de1b5a1
treed41ef34323bb897619509f70be8210dd3f7936e1
parent2278446e2b7cd33ad894b32e7eb63afc7db6c86e
usb: musb: fix remote wakeup racing with suspend

It has been observed that writing 0xF2 to the power register while it
reads as 0xF4 results in the register having the value 0xF0, i.e. clearing
RESUME and setting SUSPENDM in one go does not work. It might also violate
the USB spec to transition directly from resume to suspend, especially
when not taking T_DRSMDN into account. But this is what happens when a
remote wakeup occurs between SetPortFeature USB_PORT_FEAT_SUSPEND on the
root hub and musb_bus_suspend being called.

This commit returns -EBUSY when musb_bus_suspend is called while remote
wakeup is signalled and thus avoids to reset the RESUME bit. Ignoring
this error when musb_port_suspend is called from musb_hub_control is ok.

Signed-off-by: Daniel Glöckner <dg@emlix.com>
Signed-off-by: Bin Liu <b-liu@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/usb/musb/musb_host.c
drivers/usb/musb/musb_host.h
drivers/usb/musb/musb_virthub.c