On Tue, Sep 10, 2019 at 08:27:10AM +0200, Fabian Henneke wrote: > > > On 10.09.19 00:59, Greg Kroah-Hartman wrote: > > On Mon, Sep 09, 2019 at 03:00:46PM +0200, Fabian Henneke wrote: > >> Hi, > >> > >> On Mon, Sep 9, 2019 at 2:15 PM Pavel Machek <pa...@denx.de> wrote: > >> > >>> Hi! > >>> > >>>> [ Upstream commit 48d9cc9d85dde37c87abb7ac9bbec6598ba44b56 ] > >>>> > >>>> Let hidp_send_message return the number of successfully queued bytes > >>>> instead of an unconditional 0. > >>>> > >>>> With the return value fixed to 0, other drivers relying on hidp, such as > >>>> hidraw, can not return meaningful values from their respective > >>>> implementations of write(). In particular, with the current behavior, a > >>>> hidraw device's write() will have different return values depending on > >>>> whether the device is connected via USB or Bluetooth, which makes it > >>>> harder to abstract away the transport layer. > >>> > >>> So, does this change any actual behaviour? > >>> > >>> Is it fixing a bug, or is it just preparation for a patch that is not > >>> going to make it to stable? > >>> > >> > >> I created this patch specifically in order to ensure that user space > >> applications can use HID devices with hidraw without needing to care about > >> whether the transport is USB or Bluetooth. Without the patch, every > >> hidraw-backed Bluetooth device needs to be treated specially as its write() > >> violates the usual return value contract, which could be viewed as a bug. > >> > >> Please note that a later patch ( > >> https://www.spinics.net/lists/linux-input/msg63291.html) fixes some > >> important error checks that were relying on the old behavior (and were > >> unfortunately missed by me). > > > > As that patch doesn't seem to be in Linus's tree yet, we should postpone > > taking this one in the stable tree right now, correct? > > > > thanks, > > > > greg k-h > > > > Yes, please wait for the other patch if it's not in his tree yet and apply > the two together.
Ok, will move it out and wait for the fixup patch to hit Linus's tree, thanks! greg k-h
