For the issue that touch screen doesn't work, could you check power state of LPSS devices? For example:
cd /sys/bus/acpi/devices grep -H . */power_state If they are D3cold, it should be the reason why touch screen doesn't work. That's another issue, unrelated to this gpio patch. On 2014/4/20 18:31, Jin, Yao wrote: > > > On 2014/4/19 4:44, Benjamin Tissoires wrote: >> On Wed, Apr 16, 2014 at 8:05 AM, Jin Yao <yao....@linux.intel.com> wrote: >>> A crash is triggered on the ASUS T100TA Baytrail-T because of a irq >>> descriptor conflict. There are two gpio triggered acpi events in this >>> device, GPIO 6 and 18. These gpios are translated to irqs by calling >>> gpio_to_irq which in turn will call irq_create_mapping(vg->domain, offset). >>> irq_create_mapping will take care of allocating the irq descriptor, taking >>> the first available number starting from the given value (6 in our case). >>> The 0-15 are already reserved by legacy ISA code, so it gets the first >>> free irq descriptor which is number 16. The i915 driver also uses irq 16, >>> it loads later than gpio and crashes in probe. >>> >>> The bug is reported here: >>> https://bugzilla.kernel.org/show_bug.cgi?id=68291 >> >> Adam, the reporter of this bug told me that his touchscreen was broken >> in its tablet. > This bug is triggered when system boots, or rather, it's triggered in > i915 probe, because i915 still uses irq 16 but it's allocated for gpio > yet. It's not a touchscreen case. > >> I strongly suspect this patch to be the root cause of this, because >> the touchscreen uses i2c_hid. i2c_hid relies on an IRQ declared in the >> DSDT when it is acpi enumerated, and since the inclusion of this >> patch, no irq are triggered from a driver point of view. >> >> Adam should still confirm that the revert of the patch makes the >> touchscreen back alive, but if I understood correctly the bug report, >> without the patch, his tablet oopses at boot. > Do you mean this patch cause the touchscreen doesn't work? I suspect > that because the touch screen works on my T100 with this patch. > >> >> Still, it would be good if you could check that shifting the irqs in >> the pinctrl is or is not a problem with the irqs used for i2c devices >> (and others) declared in the dsdt. > I checked DSDT of ASUS T100, looks no irq conflict after irq shifting. > >> >> Cheers, >> Benjamin >> >>> >>> The rootcause we know now is a low level irq issue. It needs a long term >>> solution to fix the issue in irq system. >>> >>> This patch changes the Baytrail GPIO driver to avoid the irq descriptor >>> conflict. It still uses the irq domain to allocate irq descriptor but start >>> from a predefined irq base number (256) to avoid the conflict. >>> >>> Signed-off-by: Jin Yao <yao....@linux.intel.com> >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in >> the body of a message to majord...@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html >> Please read the FAQ at http://www.tux.org/lkml/ >> > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majord...@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/