From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hans de Goede Subject: Re: [PATCH] ELAN touchpad i2c_hid bugs fix Date: Mon, 25 Mar 2019 17:38:07 +0100 Message-ID: References: <20190325125704.6585-1-hotwater438@tutanota.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: Dmitry Torokhov , Vladislav Dalechyn Cc: Benjamin Tissoires , Jiri Kosina , kai.heng.feng@canonical.com, swboyd@chromium.org, bigeasy@linutronix.de, "open list:HID CORE LAYER" , lkml , hotwater438@tutanota.com List-Id: linux-input@vger.kernel.org Hi Dmitry, On 25-03-19 17:02, Dmitry Torokhov wrote: > Hi Vladislav, > > On Mon, Mar 25, 2019 at 5:57 AM Vladislav Dalechyn > wrote: >> >> From: Vladislav Dalechyn >> >> Description: The ELAN1200:04F3:303E touchpad exposes several issues, all >> caused by an error setting the correct IRQ_TRIGGER flag: >> - i2c_hid incoplete error flood in journalctl; >> - Five finger tap kill's module so you have to restart it; >> - Two finger scoll is working incorrect and sometimes even when you >> raised one of two finger still thinks that you are scrolling. >> >> Fix all of these with a new quirk that corrects the trigger flag >> announced by the ACPI tables. (edge-falling). > > I do not believe this is right solution. The driver makes liberal use > of disable_irq() and enable_irq() which may lead to lost edges and > touchpad stopping working altogether. > > Usually the "extra" report is caused by GPIO controller clearing > interrupt condition at the wrong time (too early), or in unsafe or > racy fashion. You need to look there instead of adding quirk to > i2c-hid. The falling-edge solution was proposed by Elan themselves. Also if you look at: https://bugzilla.redhat.com/show_bug.cgi?id=1543769 And esp. the "cat /proc/interrupts" output there, then you will see that the interrupt seems to be stuck at low level, which according to the ACPI tables is its active level. As for this being a GPIO chip driver problem, this is using standard Intel pinctrl stuff, which is not showing this same issue with many other i2c-hid touchpads. Regards, Hans