* [PATCH 5.11 regression-fix 0/1] ACPI: scan: Fix Battery devices sometimes never binding @ 2021-02-01 16:34 Hans de Goede 2021-02-01 16:34 ` [PATCH 1/1] " Hans de Goede 0 siblings, 1 reply; 3+ messages in thread From: Hans de Goede @ 2021-02-01 16:34 UTC (permalink / raw) To: Rafael J . Wysocki; +Cc: Hans de Goede, linux-acpi Hi Rafael, Sorry for the last minute 5.11 fix, but I only noticed this yesterday (and wrote the fix today). I believe that this was covered up by the broken acpi_bus_get_device() error handling which we debugged earlier :| For details see the actual patch. It would be nice if you can get this to Linus for 5.11. But I understand this is cutting it pretty close to the release, so if it misses 5.11 then this can be picked up by the linux-stable releases. Regards, Hans Hans de Goede (1): ACPI: scan: Fix Battery devices sometimes never binding drivers/acpi/scan.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) -- 2.29.2 ^ permalink raw reply [flat|nested] 3+ messages in thread
* [PATCH 1/1] ACPI: scan: Fix Battery devices sometimes never binding 2021-02-01 16:34 [PATCH 5.11 regression-fix 0/1] ACPI: scan: Fix Battery devices sometimes never binding Hans de Goede @ 2021-02-01 16:34 ` Hans de Goede 2021-02-01 17:56 ` Rafael J. Wysocki 0 siblings, 1 reply; 3+ messages in thread From: Hans de Goede @ 2021-02-01 16:34 UTC (permalink / raw) To: Rafael J . Wysocki; +Cc: Hans de Goede, linux-acpi With the new 2 step scanning process, which defers instantiating some ACPI-devices based on their _DEP to the second step, the following may happen: 1. During the first acpi_walk_namespace(acpi_bus_check_add) call acpi_scan_check_dep() gets called on the Battery ACPI dev handle and adds one or more deps for this handle to the acpi_dep_list 2. During the first acpi_bus_attach() call one or more of the suppliers of these deps get their driver attached and acpi_walk_dep_device_list(supplier_handle) gets called. At this point acpi_bus_get_device(dep->consumer) get called, but since the battery has DEPs it has not been instantiated during the first acpi_walk_namespace(acpi_bus_check_add), so the acpi_bus_get_device(dep->consumer) call fails. Before this commit, acpi_walk_dep_device_list() would now continue *without* removing the acpi_dep_data entry for this supplier,consumer pair from the acpi_dep_list. 3. During the second acpi_walk_namespace(acpi_bus_check_add) call an acpi_device gets instantiated for the battery and acpi_scan_dep_init() gets called to initialize its dep_unmet val. Before this commit, the dep_unmet count would include DEPs for suppliers for which acpi_walk_dep_device_list(supplier_handle) has already been called, so it will never become 0 and the ACPI battery driver will never get attached / bind. Fix the ACPI battery driver never binding in this scenario by making acpi_walk_dep_device_list() always remove matching acpi_dep_data entries independent of the acpi_bus_get_device(dep->consumer) call succeeding or not. Fixes: 71da201f38df ("ACPI: scan: Defer enumeration of devices with _DEP lists") Signed-off-by: Hans de Goede <hdegoede@redhat.com> --- drivers/acpi/scan.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index 5d7b2fcecf06..4ce54115e981 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c @@ -2123,12 +2123,12 @@ void acpi_walk_dep_device_list(acpi_handle handle) list_for_each_entry_safe(dep, tmp, &acpi_dep_list, node) { if (dep->supplier == handle) { acpi_bus_get_device(dep->consumer, &adev); - if (!adev) - continue; - adev->dep_unmet--; - if (!adev->dep_unmet) - acpi_bus_attach(adev, true); + if (adev) { + adev->dep_unmet--; + if (!adev->dep_unmet) + acpi_bus_attach(adev, true); + } list_del(&dep->node); kfree(dep); -- 2.29.2 ^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH 1/1] ACPI: scan: Fix Battery devices sometimes never binding 2021-02-01 16:34 ` [PATCH 1/1] " Hans de Goede @ 2021-02-01 17:56 ` Rafael J. Wysocki 0 siblings, 0 replies; 3+ messages in thread From: Rafael J. Wysocki @ 2021-02-01 17:56 UTC (permalink / raw) To: Hans de Goede; +Cc: Rafael J . Wysocki, ACPI Devel Maling List On Mon, Feb 1, 2021 at 5:35 PM Hans de Goede <hdegoede@redhat.com> wrote: > > With the new 2 step scanning process, which defers instantiating some > ACPI-devices based on their _DEP to the second step, the following may > happen: > > 1. During the first acpi_walk_namespace(acpi_bus_check_add) call > acpi_scan_check_dep() gets called on the Battery ACPI dev handle and > adds one or more deps for this handle to the acpi_dep_list > > 2. During the first acpi_bus_attach() call one or more of the suppliers of > these deps get their driver attached and > acpi_walk_dep_device_list(supplier_handle) gets called. > > At this point acpi_bus_get_device(dep->consumer) get called, > but since the battery has DEPs it has not been instantiated during the > first acpi_walk_namespace(acpi_bus_check_add), so the > acpi_bus_get_device(dep->consumer) call fails. > > Before this commit, acpi_walk_dep_device_list() would now continue > *without* removing the acpi_dep_data entry for this supplier,consumer > pair from the acpi_dep_list. Yeah, I've overlooked the fact that the consumer needs to have a struct acpi_device in order for the entry to be dropped from the list. Sorry. > 3. During the second acpi_walk_namespace(acpi_bus_check_add) call > an acpi_device gets instantiated for the battery and > acpi_scan_dep_init() gets called to initialize its dep_unmet val. > > Before this commit, the dep_unmet count would include DEPs for > suppliers for which acpi_walk_dep_device_list(supplier_handle) > has already been called, so it will never become 0 and the > ACPI battery driver will never get attached / bind. > > Fix the ACPI battery driver never binding in this scenario by making > acpi_walk_dep_device_list() always remove matching acpi_dep_data > entries independent of the acpi_bus_get_device(dep->consumer) call > succeeding or not. > > Fixes: 71da201f38df ("ACPI: scan: Defer enumeration of devices with _DEP lists") > Signed-off-by: Hans de Goede <hdegoede@redhat.com> Applied and thanks for fixing this! > --- > drivers/acpi/scan.c | 10 +++++----- > 1 file changed, 5 insertions(+), 5 deletions(-) > > diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c > index 5d7b2fcecf06..4ce54115e981 100644 > --- a/drivers/acpi/scan.c > +++ b/drivers/acpi/scan.c > @@ -2123,12 +2123,12 @@ void acpi_walk_dep_device_list(acpi_handle handle) > list_for_each_entry_safe(dep, tmp, &acpi_dep_list, node) { > if (dep->supplier == handle) { > acpi_bus_get_device(dep->consumer, &adev); > - if (!adev) > - continue; > > - adev->dep_unmet--; > - if (!adev->dep_unmet) > - acpi_bus_attach(adev, true); > + if (adev) { > + adev->dep_unmet--; > + if (!adev->dep_unmet) > + acpi_bus_attach(adev, true); > + } > > list_del(&dep->node); > kfree(dep); > -- > 2.29.2 > ^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2021-02-01 17:57 UTC | newest] Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2021-02-01 16:34 [PATCH 5.11 regression-fix 0/1] ACPI: scan: Fix Battery devices sometimes never binding Hans de Goede 2021-02-01 16:34 ` [PATCH 1/1] " Hans de Goede 2021-02-01 17:56 ` Rafael J. Wysocki
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.