Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Sender: Salvatore Bonaccorso <salvatore.bonaccorso@gmail.com>
Date:   Wed, 14 Apr 2021 16:02:54 +0200
From:   Salvatore Bonaccorso <carnil@debian.org>
To:     Alessandro Grassi <alessandro@aggro.it>, 986561@bugs.debian.org,
        Ioan-Adrian Ratiu <adi@adirat.com>,
        Benjamin Tissoires <benjamin.tissoires@redhat.com>,
        Jiri Kosina <jkosina@suse.cz>
Cc:     linux-input@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: Bug#986561: linux: Regression in drivers/hid/hid-dr.c causing
 horizontal D-pad to malfunction on SNES joystick
Message-ID: <YHb2Dt24465WcN1r@eldamar.lan>
References: <161779964431.889220.2857033195611862828.reportbug@malacoda>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <161779964431.889220.2857033195611862828.reportbug@malacoda>
Precedence: bulk

Hi Ioan-Adrian,

On Wed, Apr 07, 2021 at 02:47:24PM +0200, Alessandro Grassi wrote:
> Source: linux
> Severity: normal
> Tags: upstream
> X-Debbugs-Cc: alessandro@aggro.it
> 
> Greetings,
> 
> I am encountering the issue described in this thread[1], using a gamepad identified as "DragonRise" with USB ID 0079:0011.
> 
> The joypad works as intended except for the D-pad: up and down are detected in jstest (though misinterpreted: the input graph shows the points in the left up/down corners instead of the center), the left and right buttons are completely ignored.
> 
> Running 'input-events' shows events 0/127 and 255/127 on up and down respectively, nothing at all on left and right.
> 
> I was able to identify that the misbehaviour was caused by this commit[2] on the kernel source tree. To determine this I have rebuilt the Debian kernel using hid-dr.c from the previous commit[3] and loaded hid-dr.ko manually, with which the gamepad worked as intended. I have replaced the file again with the one from the breaking commit iself ([2]) and the behaviour was again broken.
> 
> Furthermore, to confirm that that was the breaking commit, I have commented line 315 (the input mapping one in the struct) from the current Debian source tree and rebuilt it, the joypad works as it should.
> 
> Regards,
> Alessandro
> 
> [1]: https://retropie.org.uk/forum/topic/25657/controler-issue-no-left-and-right-not-working-at-all
> [2]: https://github.com/torvalds/linux/commit/e15944099870f374ca7efc62f98cf23ba272ef43
> [3]: https://github.com/torvalds/linux/commit/313726cad3b68039c8e4dcad5a2840a0d375678c

A user in Debian reported that e15944099870 ("HID: hid-dr: add input
mapping for axis selection") introduced a regression, described above.

Does this ring some bell to you?

Regards,
Salvatore