On Wed, Apr 7, 2021 at 1:01 PM Angela Czubak <[email protected]> wrote: > > On Tue, Mar 30, 2021 at 5:50 PM Mika Westerberg > <[email protected]> wrote: > > > > Hi, > > > > On Tue, Mar 30, 2021 at 05:09:42PM +0200, Rafael J. Wysocki wrote: > > > On 3/29/2021 9:52 PM, Angela Czubak wrote: > > > > Do not overwrite flags as it leads to erasing triggering and polarity > > > > information which might be useful in case of hard-coded interrupts. > > > > This way the information can be read later on even though mapping to > > > > APIC domain failed. > > > > > > > > Signed-off-by: Angela Czubak <[email protected]> > > > > --- > > > > Some Chromebooks use hard-coded interrupts in their ACPI tables. > > > > This is an excerpt as dumped on Relm: > > > > > > > > ... > > > > Name (_HID, "ELAN0001") // _HID: Hardware ID > > > > Name (_DDN, "Elan Touchscreen ") // _DDN: DOS Device Name > > > > Name (_UID, 0x05) // _UID: Unique ID > > > > Name (ISTP, Zero) > > > > Method (_CRS, 0, NotSerialized) // _CRS: Current Resource > > > > Settings > > > > { > > > > Name (BUF0, ResourceTemplate () > > > > { > > > > I2cSerialBusV2 (0x0010, ControllerInitiated, > > > > 0x00061A80, > > > > AddressingMode7Bit, "\\_SB.I2C1", > > > > 0x00, ResourceConsumer, , Exclusive, > > > > ) > > > > Interrupt (ResourceConsumer, Edge, ActiveLow, > > > > Exclusive, ,, ) > > > > { > > > > 0x000000B8, > > > > } > > > > }) > > > > Return (BUF0) /* \_SB_.I2C1.ETSA._CRS.BUF0 */ > > > > } > > > > ... > > > > > > > > This interrupt is hard-coded to 0xB8 = 184 which is too high to be > > > > mapped > > > > to IO-APIC, so no triggering information is propagated as > > > > acpi_register_gsi() > > > > fails and irqresource_disabled() is issued, which leads to erasing > > > > triggering > > > > and polarity information. > > > > If that function added its flags instead of overwriting them the > > > > correct IRQ > > > > type would be set even for the hard-coded interrupts, which allows > > > > device driver > > > > to retrieve it. > > > > Please, let me know if this kind of modification is acceptable. > > > > > > From the quick look it should not be problematic, but it needs to be > > > checked > > > more carefully. > > > > > > Mika, what do you think? > > > > I think it makes sense. We still set IORESOURCE_DISABLED unconditionally > > so this should not cause issues. In theory at least :) > > > Is there anything else you would need me to do regarding the patch?
Yes, please resend it with a CC to [email protected] for more visibility. > I suppose there are more platforms that could benefit from not erasing > the flags, so if this patch is fit for upstream, can we continue the > process? > > > > > include/linux/ioport.h | 2 +- > > > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > > > > > diff --git a/include/linux/ioport.h b/include/linux/ioport.h > > > > index 55de385c839cf..647744d8514e0 100644 > > > > --- a/include/linux/ioport.h > > > > +++ b/include/linux/ioport.h > > > > @@ -331,7 +331,7 @@ static inline void irqresource_disabled(struct > > > > resource *res, u32 irq) > > > > { > > > > res->start = irq; > > > > res->end = irq; > > > > - res->flags = IORESOURCE_IRQ | IORESOURCE_DISABLED | > > > > IORESOURCE_UNSET; > > > > + res->flags |= IORESOURCE_IRQ | IORESOURCE_DISABLED | > > > > IORESOURCE_UNSET; > > > > } > > > > extern struct address_space *iomem_get_mapping(void); > > >
