On Fri, Nov 13, 2020 at 7:13 PM Sebastian Andrzej Siewior
<bigeasy@xxxxxxxxxxxxx> wrote:
>
> advance_transaction() is using in_interrupt() to distinguish between an
> invocation from the interrupt handler and an invocation from another
> part of the stack.
>
> This looks misleading because chains like
> acpi_update_all_gpes() -> acpi_ev_gpe_detect() ->
> acpi_ev_detect_gpe() -> acpi_ec_gpe_handler()
>
> should probably also behave as if they were called from an interrupt
> handler.
>
> Replace in_interrupt() usage with a function parameter. Set this
> parameter to `true' if invoked from an interrupt handler
> (acpi_ec_gpe_handler() and acpi_ec_irq_handler()) and `false' otherwise.
>
> Cc: "Rafael J. Wysocki" <rjw@xxxxxxxxxxxxx>
> Cc: Len Brown <lenb@xxxxxxxxxx>
> Cc: linux-acpi@xxxxxxxxxxxxxxx
> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
> ---
> drivers/acpi/ec.c | 21 ++++++++++-----------
> 1 file changed, 10 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c
> index e0cb1bcfffb29..0caf5ca1fc076 100644
> --- a/drivers/acpi/ec.c
> +++ b/drivers/acpi/ec.c
> @@ -169,7 +169,7 @@ struct acpi_ec_query {
> };
>
> static int acpi_ec_query(struct acpi_ec *ec, u8 *data);
> -static void advance_transaction(struct acpi_ec *ec);
> +static void advance_transaction(struct acpi_ec *ec, bool interrupt);
> static void acpi_ec_event_handler(struct work_struct *work);
> static void acpi_ec_event_processor(struct work_struct *work);
>
> @@ -358,7 +358,7 @@ static inline void acpi_ec_enable_gpe(struct acpi_ec *ec, bool open)
> * EN=1 writes.
> */
> ec_dbg_raw("Polling quirk");
> - advance_transaction(ec);
> + advance_transaction(ec, false);
> }
> }
>
> @@ -488,7 +488,7 @@ static inline void __acpi_ec_enable_event(struct acpi_ec *ec)
> * Unconditionally invoke this once after enabling the event
> * handling mechanism to detect the pending events.
> */
> - advance_transaction(ec);
> + advance_transaction(ec, false);
> }
>
> static inline void __acpi_ec_disable_event(struct acpi_ec *ec)
> @@ -632,14 +632,13 @@ static inline void ec_transaction_transition(struct acpi_ec *ec, unsigned long f
> }
> }
>
> -static void advance_transaction(struct acpi_ec *ec)
> +static void advance_transaction(struct acpi_ec *ec, bool interrupt)
> {
> struct transaction *t;
> u8 status;
> bool wakeup = false;
>
> - ec_dbg_stm("%s (%d)", in_interrupt() ? "IRQ" : "TASK",
> - smp_processor_id());
> + ec_dbg_stm("%s (%d)", interrupt ? "IRQ" : "TASK", smp_processor_id());
> /*
> * By always clearing STS before handling all indications, we can
> * ensure a hardware STS 0->1 change after this clearing can always
> @@ -699,7 +698,7 @@ static void advance_transaction(struct acpi_ec *ec)
> * otherwise will take a not handled IRQ as a false one.
> */
> if (!(status & ACPI_EC_FLAG_SCI)) {
> - if (in_interrupt() && t) {
> + if (interrupt && t) {
> if (t->irq_count < ec_storm_threshold)
> ++t->irq_count;
> /* Allow triggering on 0 threshold */
> @@ -710,7 +709,7 @@ static void advance_transaction(struct acpi_ec *ec)
> out:
> if (status & ACPI_EC_FLAG_SCI)
> acpi_ec_submit_query(ec);
> - if (wakeup && in_interrupt())
> + if (wakeup && interrupt)
> wake_up(&ec->wait);
> }
>
> @@ -767,7 +766,7 @@ static int ec_poll(struct acpi_ec *ec)
> if (!ec_guard(ec))
> return 0;
> spin_lock_irqsave(&ec->lock, flags);
> - advance_transaction(ec);
> + advance_transaction(ec, false);
> spin_unlock_irqrestore(&ec->lock, flags);
> } while (time_before(jiffies, delay));
> pr_debug("controller reset, restart transaction\n");
> @@ -1216,7 +1215,7 @@ static void acpi_ec_check_event(struct acpi_ec *ec)
> * taking care of it.
> */
> if (!ec->curr)
> - advance_transaction(ec);
> + advance_transaction(ec, false);
> spin_unlock_irqrestore(&ec->lock, flags);
> }
> }
> @@ -1259,7 +1258,7 @@ static void acpi_ec_handle_interrupt(struct acpi_ec *ec)
> unsigned long flags;
>
> spin_lock_irqsave(&ec->lock, flags);
> - advance_transaction(ec);
> + advance_transaction(ec, true);
> spin_unlock_irqrestore(&ec->lock, flags);
> }
>
> --
Applied (with minor edits in the subject) as 5.11 material, thanks!
