| Message ID | 20170409195918.20864-1-hdegoede@redhat.com (mailing list archive) |
|---|---|
| State | RFC, archived |
| Headers | show |
Hi Hans, On 09/04/17 20:59, Hans de Goede wrote: > While writing a driver for the INT0002 ACPI device found on Intel > Bay and Cherry Trail devices I hit the following error: > > "genirq: Flags mismatch irq 9. 00000084 (INT0002) vs. 00000080 (acpi)" > > This is caused by drivers/acpi/osl.c first doing: > > request_irq(irq, acpi_irq, IRQF_SHARED, "acpi", acpi_irq) > > While the irqdata for the irq contains no trigger flags, resulting > in an irqaction with IRQF_TRIGGER_NONE. > > And then the INT0002 driver I'm working on calling platform_get_irq > which does: irqd_set_trigger_type(irqd, r->flags & IORESOURCE_BITS); > > And then request_irq(irq, ..., IRQF_SHARED, ...) on the irq returned > by platform_get_irq causes the error quoted above. > > Arguably the genirq code should not hit the shared irq trigger-flags > mismatch code if the old irqaction has IRQF_TRIGGER_NONE as flags. > > This patch is an attempt at fixing this, but I'm not sure it is the > right fix, hence it RFC status. > > Signed-off-by: Hans de Goede <hdegoede@redhat.com> > --- > kernel/irq/manage.c | 7 ++++++- > 1 file changed, 6 insertions(+), 1 deletion(-) > > diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c > index a4afe5c..24e5eef 100644 > --- a/kernel/irq/manage.c > +++ b/kernel/irq/manage.c > @@ -1212,8 +1212,13 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new) > * set the trigger type must match. Also all must > * agree on ONESHOT. > */ > + unsigned int old_msk = old->flags & IRQF_TRIGGER_MASK; > + > + if (!old_msk) > + old_msk = irqd_get_trigger_type(&desc->irq_data); > + > if (!((old->flags & new->flags) & IRQF_SHARED) || > - ((old->flags ^ new->flags) & IRQF_TRIGGER_MASK) || > + ((old_msk ^ new->flags) & IRQF_TRIGGER_MASK) || > ((old->flags ^ new->flags) & IRQF_ONESHOT)) > goto mismatch; > > I'm afraid you're just papering over the issue here, as you leave the "old" descriptor in an inconsistent state w.r.t. the "new" descriptor. My view is that the old irq_desc should be "upgraded" to the new trigger configuration, because they are sharing a line and must have compatible behaviours. NONE is effectively a wildcard, and the second interrupt request should turn this wildcard into the real thing. The opposite case also exists (request a LEVEL interrupt first, then a NONE), and should be resolved the same way (NONE becomes LEVEL). Thoughts? M.
HI, On 10-04-17 12:13, Marc Zyngier wrote: > Hi Hans, > > On 09/04/17 20:59, Hans de Goede wrote: >> While writing a driver for the INT0002 ACPI device found on Intel >> Bay and Cherry Trail devices I hit the following error: >> >> "genirq: Flags mismatch irq 9. 00000084 (INT0002) vs. 00000080 (acpi)" >> >> This is caused by drivers/acpi/osl.c first doing: >> >> request_irq(irq, acpi_irq, IRQF_SHARED, "acpi", acpi_irq) >> >> While the irqdata for the irq contains no trigger flags, resulting >> in an irqaction with IRQF_TRIGGER_NONE. >> >> And then the INT0002 driver I'm working on calling platform_get_irq >> which does: irqd_set_trigger_type(irqd, r->flags & IORESOURCE_BITS); >> >> And then request_irq(irq, ..., IRQF_SHARED, ...) on the irq returned >> by platform_get_irq causes the error quoted above. >> >> Arguably the genirq code should not hit the shared irq trigger-flags >> mismatch code if the old irqaction has IRQF_TRIGGER_NONE as flags. >> >> This patch is an attempt at fixing this, but I'm not sure it is the >> right fix, hence it RFC status. >> >> Signed-off-by: Hans de Goede <hdegoede@redhat.com> >> --- >> kernel/irq/manage.c | 7 ++++++- >> 1 file changed, 6 insertions(+), 1 deletion(-) >> >> diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c >> index a4afe5c..24e5eef 100644 >> --- a/kernel/irq/manage.c >> +++ b/kernel/irq/manage.c >> @@ -1212,8 +1212,13 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new) >> * set the trigger type must match. Also all must >> * agree on ONESHOT. >> */ >> + unsigned int old_msk = old->flags & IRQF_TRIGGER_MASK; >> + >> + if (!old_msk) >> + old_msk = irqd_get_trigger_type(&desc->irq_data); >> + >> if (!((old->flags & new->flags) & IRQF_SHARED) || >> - ((old->flags ^ new->flags) & IRQF_TRIGGER_MASK) || >> + ((old_msk ^ new->flags) & IRQF_TRIGGER_MASK) || >> ((old->flags ^ new->flags) & IRQF_ONESHOT)) >> goto mismatch; >> >> > > I'm afraid you're just papering over the issue here, as you leave the > "old" descriptor in an inconsistent state w.r.t. the "new" descriptor. > > My view is that the old irq_desc should be "upgraded" to the new trigger > configuration, because they are sharing a line and must have compatible > behaviours. There is no old irq_desc only an old ircaction, but yes that can easily be updated to reflect the mask from the irq_data, or maybe we should not use the oldaction for the trigger_mask bits at all and instead use the trigger_mask from the irq_data as done in: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/kernel/irq/manage.c?id=7ee7e87dfb158e79019ea1d5ea1b0e6f2bc93ee4 For a different code path ? Thomas? > NONE is effectively a wildcard, and the second interrupt > request should turn this wildcard into the real thing. > > The opposite case also exists (request a LEVEL interrupt first, then a > NONE), and should be resolved the same way (NONE becomes LEVEL). The 2nd order of requesting irqs will already work because of: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/kernel/irq/manage.c?id=4b357daed698c95d6b5eacc1c3c4afa206071ba2 Where the new_action trigger_mask gets filled with the triger_mask from the irq_data, which is a further hint that looking at irqd_get_trigger_type(&desc->irq_data) rather then at (old->flags IRQF_TRIGGER_MASK) is probably the right fix. Note btw that 4b357daed698 is (part of) what is breaking things for my use-case, I request the irq with IRQF_TRIGGER_NONE but 4b357daed698 modifies that before comparing the new trigger flags to the old. Regards, Hans -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Mon, 10 Apr 2017, Hans de Goede wrote: > Where the new_action trigger_mask gets filled with the triger_mask > from the irq_data, which is a further hint that looking at > irqd_get_trigger_type(&desc->irq_data) rather then at > (old->flags IRQF_TRIGGER_MASK) is probably the right fix. > > Note btw that 4b357daed698 is (part of) what is breaking things for > my use-case, I request the irq with IRQF_TRIGGER_NONE but > 4b357daed698 modifies that before comparing the new trigger flags > to the old. The issue here is, that at the time of the first setup_irq() the trigger type in irq_data is NONE. As a consequence the following is a NOOP: if (!new->trigger) new->flags |= get_type(irqdata); Now the irq is started up for the first time and then the actual trigger type gets established, but that's to late to fix up new->flags. So yes, we should change the logic for the shared case to: if (old) { oldtype = get_type(irqdata); if (oldtype != newtype) goto mismatch; That should cover all cases. Thanks, tglx -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index a4afe5c..24e5eef 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -1212,8 +1212,13 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new) * set the trigger type must match. Also all must * agree on ONESHOT. */ + unsigned int old_msk = old->flags & IRQF_TRIGGER_MASK; + + if (!old_msk) + old_msk = irqd_get_trigger_type(&desc->irq_data); + if (!((old->flags & new->flags) & IRQF_SHARED) || - ((old->flags ^ new->flags) & IRQF_TRIGGER_MASK) || + ((old_msk ^ new->flags) & IRQF_TRIGGER_MASK) || ((old->flags ^ new->flags) & IRQF_ONESHOT)) goto mismatch;
While writing a driver for the INT0002 ACPI device found on Intel Bay and Cherry Trail devices I hit the following error: "genirq: Flags mismatch irq 9. 00000084 (INT0002) vs. 00000080 (acpi)" This is caused by drivers/acpi/osl.c first doing: request_irq(irq, acpi_irq, IRQF_SHARED, "acpi", acpi_irq) While the irqdata for the irq contains no trigger flags, resulting in an irqaction with IRQF_TRIGGER_NONE. And then the INT0002 driver I'm working on calling platform_get_irq which does: irqd_set_trigger_type(irqd, r->flags & IORESOURCE_BITS); And then request_irq(irq, ..., IRQF_SHARED, ...) on the irq returned by platform_get_irq causes the error quoted above. Arguably the genirq code should not hit the shared irq trigger-flags mismatch code if the old irqaction has IRQF_TRIGGER_NONE as flags. This patch is an attempt at fixing this, but I'm not sure it is the right fix, hence it RFC status. Signed-off-by: Hans de Goede <hdegoede@redhat.com> --- kernel/irq/manage.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)