Return-Path: Date: Wed, 26 Nov 2014 15:12:07 +0100 Message-ID: From: Takashi Iwai To: Marcel Holtmann Cc: Oliver Neukum , Dave Jones , Linux Kernel , pgynther@google.com, linux-bluetooth@vger.kernel.org Subject: Re: bluetooth related firmware loader spew on resume. In-Reply-To: <0E1D95E7-64D2-4BEA-AFAA-4B119838F24E@holtmann.org> References: <20141111181228.GA27815@redhat.com> <1416996623.3171.7.camel@linux-0dmf.site> <0E1D95E7-64D2-4BEA-AFAA-4B119838F24E@holtmann.org> MIME-Version: 1.0 (generated by SEMI 1.14.6 - "Maruoka") Content-Type: text/plain; charset=US-ASCII List-ID: At Wed, 26 Nov 2014 23:05:20 +0900, Marcel Holtmann wrote: > > Hi Oliver, > > >> In order to paper over this, we may also remember the failing firmware > >> and avoid loading it. This might be an easer way than the endless > >> fight against UMH race... > > > > > > the full fix would be to implement reset_resume() for btusb. > > It seems to me that setup() should be split in two methods, > > one to request the firmware from user space and the second > > to transfer it to the device. reset_resume() would just need > > to repeat the second operation. > > so when you do hci_register_dev, then hdev->setup is only called once. I really mean only once per lifetime of the hci_dev. So you would need to unregister the hci_dev first before hdev->setup will ever be called again. So I am not sure this is actually the problem here. The problem here is entirely within request_firmware() unless of course we run through the USB probe handlers again. Which I do not see happening here. > > And we have hdev->setup this way since normally the Bluetooth devices keep their firmware patches and not forget about them and suspend-resume cycles. If the USB device of course jumps of the bus during it then all bets are off anyway. Usually you can avoid unnecessary rebinding when you provide a proper reset_resume callback. I guess that's what Oliver suggested. Takashi