From: Sebastian Andrzej Siewior Date: Mon, 27 Oct 2014 18:06:19 +0000 (+0100) Subject: usb: musb: try a race-free wakeup X-Git-Tag: omap-for-v3.19/fixes-rc1~87^2~32^2~95 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=baadd52f0aa7a100192661132299f13e763932df;p=pandora-kernel.git usb: musb: try a race-free wakeup Attaching a keyboard, using it as a wakeup via |for f in $(find /sys/devices/ocp.3/47400000.usb -name wakeup) |do | echo enabled > $f |done going into standby | echo standby > /sys/power/state and now a wake up by a pressing a key. What happens is that the system wakes up but the USB device is dead. The USB stack tries to send a few control URBs but nothing comes back. Eventually it gaves up and the device remains dead: |[ 632.559678] PM: Wakeup source USB1_PHY |[ 632.581074] PM: noirq resume of devices complete after 21.261 msecs |[ 632.607521] PM: early resume of devices complete after 10.360 msecs |[ 632.616854] net eth2: initializing cpsw version 1.12 (0) |[ 632.704126] net eth2: phy found : id is : 0x4dd074 |[ 636.704048] libphy: 4a101000.mdio:00 - Link is Up - 1000/Full |[ 638.444620] usb 1-1: reset low-speed USB device number 2 using musb-hdrc |[ 653.713435] usb 1-1: device descriptor read/64, error -110 |[ 669.093435] usb 1-1: device descriptor read/64, error -110 |[ 669.473424] usb 1-1: reset low-speed USB device number 2 using musb-hdrc |[ 684.743436] usb 1-1: device descriptor read/64, error -110 |[ 690.065097] PM: resume of devices complete after 57450.744 msecs |[ 690.076601] PM: Finishing wakeup. |[ 690.076627] Restarting tasks ... It seems that since we got woken up via MUSB_INTR_RESUME the musb_host_finish_resume() callback is executed before the resume-callbacks of the PHY and glue layer are invoked. If I delay it until the glue layer resumed then I don't see this problem. I also move musb_host_resume_root_hub() into that callback since I don't see any reason in doing anything resume-link if there are still pieces not restored. Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Felipe Balbi --- Reading git-diff-tree failed