On Wed, Jan 7, 2015 at 11:26 PM, Johan Hovold <johan@xxxxxxxxxx> wrote: > On Tue, Dec 16, 2014 at 05:57:15PM +0200, Octavian Purdila wrote: >> Without suspend/resume functionality in the USB driver the USB core >> will disconnect and reconnect the DLN2 port and because the GPIO >> framework does not yet support removal of an in-use controller a >> suspend/resume operation will result in a crash. >> >> This patch provides suspend and resume functions for the DLN2 driver >> so that the above scenario is avoided. >> >> Signed-off-by: Octavian Purdila <octavian.purdila@xxxxxxxxx> > > This patch looks good now, but how did you say this device was powered? > > If powered by vbus you cannot assume that the device maintains it's > state over a suspend cycle, something which would complicate matters > quite a bit... > Yes, the device is powered by VBUS. During my tests, depending on the host and USB port, VBUS is sometimes preserved - and this is the case this patch addresses, and sometimes is not, but in that case because no reset_resume routine is implemented the resume path will go through the disconnect/reconnect process. This second case is not addressed by the patch, as I think in this second case fixing the GPIO framework to support the removal of an in-use device is the best way to go. -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
