CVS commit: [netbsd-10] src/sys

["Martin Husemann" <martin%netbsd.org@localhost>]

Module Name:    src
Committed By:   martin
Date:           Sun Jul 30 12:01:54 UTC 2023

Modified Files:
        src/sys/arch/amd64/conf [netbsd-10]: ALL
        src/sys/arch/i386/conf [netbsd-10]: ALL
        src/sys/dev/acpi [netbsd-10]: acpi_ec.c files.acpi

Log Message:
Pull up following revision(s) (requested by riastradh in ticket #259):

        sys/dev/acpi/acpi_ec.c: revision 1.102
        sys/dev/acpi/acpi_ec.c: revision 1.103
        sys/dev/acpi/acpi_ec.c: revision 1.104
        sys/dev/acpi/acpi_ec.c: revision 1.105
        sys/dev/acpi/acpi_ec.c: revision 1.106
        sys/dev/acpi/acpi_ec.c: revision 1.107
        sys/dev/acpi/acpi_ec.c: revision 1.108
        sys/dev/acpi/acpi_ec.c: revision 1.90
        sys/dev/acpi/acpi_ec.c: revision 1.91
        sys/dev/acpi/acpi_ec.c: revision 1.92
        sys/dev/acpi/acpi_ec.c: revision 1.93
        sys/dev/acpi/acpi_ec.c: revision 1.94
        sys/dev/acpi/files.acpi: revision 1.128
        sys/dev/acpi/acpi_ec.c: revision 1.95
        sys/dev/acpi/acpi_ec.c: revision 1.96
        sys/dev/acpi/acpi_ec.c: revision 1.97
        sys/arch/amd64/conf/ALL: revision 1.179
        sys/dev/acpi/acpi_ec.c: revision 1.98
        sys/dev/acpi/acpi_ec.c: revision 1.99
        sys/dev/acpi/acpi_ec.c: revision 1.87
        sys/dev/acpi/acpi_ec.c: revision 1.88
        sys/dev/acpi/acpi_ec.c: revision 1.89
        sys/arch/i386/conf/ALL: revision 1.511
        sys/dev/acpi/acpi_ec.c: revision 1.100
        sys/dev/acpi/acpi_ec.c: revision 1.101

acpiec(4): Record device_t self.

Not used yet, to be used soon for device_printf and to allow making
some of the internal functions a little more type-safe later.
acpiec(4): New ACPIEC_DEBUG option.

Value is bit mask of debug messages to enable.

Enable in x86/ALL kernels.

No functional change intended when the option is off.

acpiec(4): Clarify lock order and sprinkle lock assertions.
No functional change intended.

acpiec(4): Sprinkle comments.
Note where this code is abusing cv_wait and needs a loop to handle
spurious wakeups.
No functional change intended.

acpiec(4): Assert state is free when we start a transaction.
No functional change intended.

acpiec(4): Set sc_got_sci only when a transaction is over.

Before, when the acpiec thread noticed an SCI had been requested and
entered acpiec_gpe_state_machine to send the query command, it would
see the SCI is still requested -- because it had yet to acknowledge
it by setting the query command! -- and think the EC was asking for a
_second_ SCI.

So once the first SCI transaction was over, it would start a second
one, even though the EC hadn't asked for another -- and this would
wedge on some ECs.

Now, acpiec_gpe_state_machine waits to see what state we transition
to before taking the SCI bit to mean we need to notify the acpiec
thread to handle another query.

That way, when the acpiec thread enters acpiec_gpe_state_machine with
EC_STATE_QUERY, it can send the query command first, with the side
effect of clearing the SCI bit in subsequent reads of the status
register, and it won't think another SCI has been requested until it
returns to EC_STATE_FREE and sees the SCI bit set again in the status
register.

Possibly relevant PRs:
PR kern/53135
PR kern/52763
PR kern/57162

acpiec(4): Fix cv_wait loop around sc->sc_got_sci.

That is, make it actually loop as required, so it gracefully handles
spurious wakeups instead of barging into invalid states.

acpiec(4): Fix interrupt wait loop in acpiec_gpe_query thread.

acpiec(4): Fix cv_timedwait abuse in acpiec_read/write.

acpiec(4): Don't touch sc->sc_state outside sc->sc_mtx.

acpiec(4): Merge returns in acpiec_read/write.
No functional change intended.

acpiec(4): Factor wait logic out.
No functional change intended.

acpiec(4): Pass softc, not device_t, to acpiec_gpe_state_machine.
Simpler, type-safer.
No functional change intended.

acpiec(4): Pass softc, not device_t, to acpiec_callout.
Simpler.
No functional change intended.

acpiec(4): Pass softc, not device_t, to acpiec_gpe_handler.
Simpler.
No functional change intended.

acpiec(4): Pass softc, not device_t, to acpiec_lock/unlock.
Simpler, type-safer.
No functional change intended.

acpiec(4): Pass softc, not device_t, to acpiec_read/write.
Simpler, type-safer.
No functional change intended.

acpiec(4): Pass softc, not device_t, to acpiec_gpe_query thread.
Simpler.
No functional change intended.

acpiec(4): Pass softc, not device_t, to acpiec_space_handler.
Better to keep the device_t isolated to public interfaces.  Simpler
internally this way.
No functional change intended.

acpiec(4): Factor out if (state == FREE) cv_signal(sc_cv).

In principle this could have a functional change, but at worst, it is
to signal more wakeups than needed, which should always be safe.
acpiec(4): Take a lock around acpiec_cold updates.

Otherwise we race with readers -- probably harmlessly, but let's
avoid the appearance of problems.
XXX Maybe acpiec_suspend and acpiec_shutdown should interrupt
transactions and force them to fail promptly?
XXX This looks bad because acpiec_cold is global and sc->sc_mtx
doesn't look like it's global, but we expect to have only one
acpiec(4) device anyway from what I understand.  Maybe we should move
acpiec_cold into the softc?

acpiec(4): One more debug message about read/write polling timeout.


To generate a diff of this commit:
cvs rdiff -u -r1.174 -r1.174.4.1 src/sys/arch/amd64/conf/ALL
cvs rdiff -u -r1.503 -r1.503.4.1 src/sys/arch/i386/conf/ALL
cvs rdiff -u -r1.86 -r1.86.4.1 src/sys/dev/acpi/acpi_ec.c
cvs rdiff -u -r1.126 -r1.126.4.1 src/sys/dev/acpi/files.acpi

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.