Re: [PATCH] ELAN touchpad i2c_hid bugs fix

[Hans de Goede <hdegoede@redhat.com>]

Hi,

On 15-04-19 13:36, hotwater438@tutanota.com wrote:
> Sorry for the delay.
> By applying this patch I get next results:
> Five finger tap and two finger scroll issues disappear, but after suspend touchpad dies. Restarting module doesn't help.

So bascally the same results as with the edge-triggered interrupt patch/hack,
right?

Are you still using the edge-triggered interrupt patch, or just the new
patch Kai-Heng Feng provided.

To me it sounds like the patch Kai-Heng Feng provided at least removes
the need for the edge-triggered interrupt patch/hack and what remains to
be solved is the suspend/resume issues.

Regards,

Hans



> Here's the log:
> 
> Apr 15 14:35:54 parrot sudo[3473]: h0tw4t3r : TTY=pts/1 ; PWD=/home/h0tw4t3r ; USER=root ; COMMAND=/sbin/rmmod i2c_hid
> Apr 15 14:35:54 parrot sudo[3478]: h0tw4t3r : TTY=pts/1 ; PWD=/home/h0tw4t3r ; USER=root ; COMMAND=/sbin/modprobe i2c_hid
> Apr 15 14:35:54 parrot kernel: i2c_hid i2c-ELAN1200:00: i2c-ELAN1200:00 supply vdd not found, using dummy regulator
> Apr 15 14:35:54 parrot kernel: i2c_hid i2c-ELAN1200:00: i2c-ELAN1200:00 supply vddl not found, using dummy regulator
> 
> Could you please explain what this patch does?
> 
> Regards,
> Vladislav.
> 
> Apr 13, 2019, 11:42 AM by kai.heng.feng@canonical.com:
> 
>     at 16:40, <hotwater438@tutanota.com <mailto:hotwater438@tutanota.com>> <hotwater438@tutanota.com <mailto:hotwater438@tutanota.com>> wrote:
> 
>         Hi.
> 
>         I've applied this patch, but still getting incomplete report messages.
> 
> 
>     Does the patch fix the other two issues:
>     - 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.
> 
>     Kai-Heng
> 
> 
>         Regards,
>         Vladislav
> 
>         Apr 11, 2019, 7:17 PM by kai.heng.feng@canonical.com <mailto:kai.heng.feng@canonical.com>:
>         Hi,
> 
>         at 05:18, <hotwater438@tutanota.com <mailto:hotwater438@tutanota.com>> <hotwater438@tutanota.com <mailto:hotwater438@tutanota.com>> wrote:
>         Hi.
> 
>         1) Run "cat /proc/interrupts | grep ELAN" , note down the value
>         2) Very quickly/briefly touch the touchpad once
>         3) Run "cat /proc/interrupts | grep ELAN" , note down the value again
>         4) Subtract result from 1. from result from 3, this difference is
>         the value we are interested in. E.g. my testing got 254 and 257, so
>         a difference of 3.
>         I've tested that, main diffs are 30, 24, 16 (the most frequent), 2 (the least frequent).
> 
>         I was using 4.19.13 kernel, because I use ParrotOS (which happens to be Debian distribution).
>         But I've installed experimental 5.0.0 kernel and I can't say right now if suspend problem is resolved (i have to rebuild latest kernel with patch).
> 
>         Can you try below fix?
> 
>         This can solve what commit 1475af255e18 ("HID: i2c-hid: Ignore input report if there's no data present on Elan touchpanels”) tries to workaround.
> 
>         diff --git a/drivers/pinctrl/intel/pinctrl-intel.c b/drivers/pinctrl/intel/pinctrl-intel.c
>         index c19a4c45f7bb..30e3664f1ae5 100644
>         --- a/drivers/pinctrl/intel/pinctrl-intel.c
>         +++ b/drivers/pinctrl/intel/pinctrl-intel.c
>         @@ -957,6 +957,10 @@ static void intel_gpio_irq_mask_unmask(struct irq_data *d, bool mask)
>         reg = community->regs + community->ie_offset + gpp * 4;
> 
>         raw_spin_lock_irqsave(&pctrl->lock, flags);
>         +
>         + if (!mask)
>         + writel(BIT(gpp_offset), community->regs + community->is_offset + gpp * 4);
>         +
>         value = readl(reg);
>         if (mask)
>         value &= ~BIT(gpp_offset);
> 
> 
>         Regards,
>         Vladislav.
> 
>         Apr 3, 2019, 2:18 PM by hdegoede@redhat.com <mailto:hdegoede@redhat.com>:
>         Hi,
> 
>         On 31-03-19 11:50, hotwater438@tutanota.com <mailto:hotwater438@tutanota.com> wrote:
>         Hi. I've done everything you said, here are results:
> 
>         Vladislav can you check the output of /cat/interrupts on a kernel
>         without the patch and while *not* using the touchpad; and check
>         if the amount of touchpads-interrupts still keeps increasing in this
>         case?
> 
>         IWI or IRQ work interrupts keep increasing with speed at least 3 interrupts/s.
> 
>         I'm really only interested in the touchpad related IRQs, so e.g. the line
>         about "intel-gpio 129 ELAN1200:00", if you're seeing 3 interrupts/s on
>         some others that is fine, so I take it the ELAN1200:00 interrupt count
>         does not increase on an *unpatched* kernel, unless you use the touchpad?
>         Also when I am moving touchpad IR-IO-APIC 14-fasteoi INT345D:00 get's triggered and increased.
> 
>         That is the GPIO controller interrupt, so that one increasing is normal.
> 
>         If I understand things correctly then this all means that the IRQ indeed
>         is a normal level IRQ and Dmitry is likely correct that there is an
>         pinctrl / gpiochip driver problem here.
> 
>         Can you try the following with an *unpatched* kernel? :
> 
>         1) Run "cat /proc/interrupts | grep ELAN" , note down the value
>         2) Very quickly/briefly touch the touchpad once
>         3) Run "cat /proc/interrupts | grep ELAN" , note down the value again
>         4) Subtract result from 1. from result from 3, this difference is
>         the value we are interested in. E.g. my testing got 254 and 257, so
>         a difference of 3.
> 
>         The goal here is to get an as low as possible difference. Feel free
>         to repeat this a couple of times.
> 
>         On an Apollo Lake laptop with an I2C hid mt touchpad I can get the
>         amount of interrupts triggered for a single touch down to 3,
>         given the huge interrupt counts of 130000+ reported in:
>         https://bugzilla.redhat.com/show_bug.cgi?id=1543769
> 
>         I expect you to get a much bigger smallest possible difference
>         between 2 "cat /proc/interrupts | grep ELAN" commands, note a
>         difference of 0 means your touch did not register.
> 
>         Assuming you indeed see much more interrupts for a very quick
>         touch + release, then we indeed have an interrupt handling problem
>         we need to investigate further.
>         I don't know if it's important or not, but for some reason these interrupts keep popping only on CPU2 (i have 4cpu processor).
> 
>         That does not matter.
>         1) Suspending the machine by selecting suspend from a menu in your
>         desktop environment, or by briefly pressing the power-button, do
>         not close the lid
>         2) As soon as the system starts suspending and while it is suspended, move
>         your finger around the touchpad
>         3) Wake the system up with the powerbutton while moving your finger around
>         4) Check if the touchpad still works after this
> 
>         It works, but as it seems, looses edge. JournalCTL is being flooded with i2c_hid_get_input: incomplete report (16/65535)
> 
>         That is probably a different issue. If you loose the edge IRQ, then the touchpad
>         would stop working without any messages. I believe that the suspend / resume
>         issue may be fixed by:
>         https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=52cf93e63ee672a92f349edc6ddad86ec8808fd8
> 
>         Does your kernel have this commit? (please always use the latest kernel while
>         testing).
>         Also a thing to notice, that after manually removing and modprobing i2c_hid module, it says next in journalctl:
> 
>         i2c_hid i2c-ELAN1200:00: i2c-ELAN1200:00 supply vdd not found, using dummy regulator
>         i2c_hid i2c-ELAN1200:00: i2c-ELAN1200:00 supply vddl not found, using dummy regulator
> 
>         Those messages can safely be ignored.
> 
>         Regards,
> 
>         Hans
> 
>