Re: [PATCH AUTOSEL 5.19 16/36] ACPI: video: Change disable_backlight_sysfs_if quirks to acpi_backlight=native

Hans de Goede
2022-10-10T07:40:50Z

Hi,

On 10/10/22 01:52, Sasha Levin wrote:
> From: Hans de Goede <hdegoede@redhat.com>
>
> [ Upstream commit c5b94f5b7819348c59f9949b2b75c341a114cdd4 ]
>
> Some Toshibas have a broken acpi-video interface for brightness control
> and need a special firmware call on resume to turn the panel back on.
> So far these have been using the disable_backlight_sysfs_if workaround
> to deal with this.
>
> The recent x86/acpi backlight refactoring has broken this workaround:
> 1. This workaround relies on acpi_video_get_backlight_type() returning
> acpi_video so that the acpi_video code actually runs; and
> 2. this relies on the actual native GPU driver to offer the sysfs
> backlight interface to userspace.
>
> After the refactor this breaks since the native driver will no
> longer register its backlight-device if acpi_video_get_backlight_type()
> does not return native and making it return native breaks 1.
>
> Keeping the acpi_video backlight handling on resume active, while not
> using it to set the brightness, is necessary because it does a _BCM
> call on resume which is necessary to turn the panel back on on resume.
>
> Looking at the DSDT shows that this _BCM call results in a Toshiba
> HCI_SET HCI_LCD_BRIGHTNESS call, which turns the panel back on.
>
> This kind of special vendor specific handling really belongs in
> the vendor specific acpi driver. An earlier patch in this series
> modifies toshiba_acpi to make the necessary HCI_SET call on resume
> on affected models.
>
> With toshiba_acpi taking care of the HCI_SET call on resume,
> the acpi_video code no longer needs to call _BCM on resume.
>
> So instead of using the (now broken) disable_backlight_sysfs_if
> workaround, simply setting acpi_backlight=native to disable
> the broken apci-video interface is sufficient fix things now.
>
> After this there are no more users of the disable_backlight_sysfs_if
> flag and as discussed above the flag also no longer works as intended,
> so remove the disable_backlight_sysfs_if flag entirely.
>
> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> Tested-by: Arvid Norlander <lkml@vorpal.se>
> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
> Signed-off-by: Sasha Levin <sashal@kernel.org>

This patch goes hand in hand with:

commit 3cb1f40dfdc3 ("drivers/platform: toshiba_acpi: Call HCI_PANEL_POWER_ON on resume on some models")

and without that commit also being present it will cause a regression on
the quirkes Toshiba models.

This really is part of the big x86/ACPI backlight handling refactor which
has landed in 6.1 and as such is not intended for older kernels, please
drop this from the stable series.

Regards,

Hans

> ---
> drivers/acpi/acpi_video.c | 48 -------------------------------------
> drivers/acpi/video_detect.c | 35 +++++++++++++++++++++++++++
> 2 files changed, 35 insertions(+), 48 deletions(-)
>
> diff --git a/drivers/acpi/acpi_video.c b/drivers/acpi/acpi_video.c
> index eaea733b368a..bd972d28df5d 100644
> --- a/drivers/acpi/acpi_video.c
> +++ b/drivers/acpi/acpi_video.c
> @@ -47,9 +47,6 @@ module_param(brightness_switch_enabled, bool, 0644);
> static bool allow_duplicates;
> module_param(allow_duplicates, bool, 0644);
>
> -static int disable_backlight_sysfs_if = -1;
> -module_param(disable_backlight_sysfs_if, int, 0444);
> -
> #define REPORT_OUTPUT_KEY_EVENTS 0x01
> #define REPORT_BRIGHTNESS_KEY_EVENTS 0x02
> static int report_key_events = -1;
> @@ -382,14 +379,6 @@ static int video_set_bqc_offset(const struct dmi_system_id *d)
> return 0;
> }
>
> -static int video_disable_backlight_sysfs_if(
> - const struct dmi_system_id *d)
> -{
> - if (disable_backlight_sysfs_if == -1)
> - disable_backlight_sysfs_if = 1;
> - return 0;
> -}
> -
> static int video_set_device_id_scheme(const struct dmi_system_id *d)
> {
> device_id_scheme = true;
> @@ -462,40 +451,6 @@ static const struct dmi_system_id video_dmi_table[] = {
> },
> },
>
> - /*
> - * Some machines have a broken acpi-video interface for brightness
> - * control, but still need an acpi_video_device_lcd_set_level() call
> - * on resume to turn the backlight power on. We Enable backlight
> - * control on these systems, but do not register a backlight sysfs
> - * as brightness control does not work.
> - */
> - {
> - /* https://bugzilla.kernel.org/show_bug.cgi?id=21012 */
> - .callback = video_disable_backlight_sysfs_if,
> - .ident = "Toshiba Portege R700",
> - .matches = {
> - DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
> - DMI_MATCH(DMI_PRODUCT_NAME, "PORTEGE R700"),
> - },
> - },
> - {
> - /* https://bugs.freedesktop.org/show_bug.cgi?id=82634 */
> - .callback = video_disable_backlight_sysfs_if,
> - .ident = "Toshiba Portege R830",
> - .matches = {
> - DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
> - DMI_MATCH(DMI_PRODUCT_NAME, "PORTEGE R830"),
> - },
> - },
> - {
> - /* https://bugzilla.kernel.org/show_bug.cgi?id=21012 */
> - .callback = video_disable_backlight_sysfs_if,
> - .ident = "Toshiba Satellite R830",
> - .matches = {
> - DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
> - DMI_MATCH(DMI_PRODUCT_NAME, "SATELLITE R830"),
> - },
> - },
> /*
> * Some machine's _DOD IDs don't have bit 31(Device ID Scheme) set
> * but the IDs actually follow the Device ID Scheme.
> @@ -1767,9 +1722,6 @@ static void acpi_video_dev_register_backlight(struct acpi_video_device *device)
> if (result)
> return;
>
> - if (disable_backlight_sysfs_if > 0)
> - return;
> -
> name = kasprintf(GFP_KERNEL, "acpi_video%d", count);
> if (!name)
> return;
> diff --git a/drivers/acpi/video_detect.c b/drivers/acpi/video_detect.c
> index 5d7f38016a24..c370de174fd3 100644
> --- a/drivers/acpi/video_detect.c
> +++ b/drivers/acpi/video_detect.c
> @@ -514,6 +514,41 @@ static const struct dmi_system_id video_detect_dmi_table[] = {
> DMI_MATCH(DMI_BOARD_NAME, "PF5LUXG"),
> },
> },
> + /*
> + * These Toshibas have a broken acpi-video interface for brightness
> + * control. They also have an issue where the panel is off after
> + * suspend until a special firmware call is made to turn it back
> + * on. This is handled by the toshiba_acpi kernel module, so that
> + * module must be enabled for these models to work correctly.
> + */
> + {
> + /* https://bugzilla.kernel.org/show_bug.cgi?id=21012 */
> + .callback = video_detect_force_native,
> + /* Toshiba Portégé R700 */
> + .matches = {
> + DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
> + DMI_MATCH(DMI_PRODUCT_NAME, "PORTEGE R700"),
> + },
> + },
> + {
> + /* Portégé: https://bugs.freedesktop.org/show_bug.cgi?id=82634 */
> + /* Satellite: https://bugzilla.kernel.org/show_bug.cgi?id=21012 */
> + .callback = video_detect_force_native,
> + /* Toshiba Satellite/Portégé R830 */
> + .matches = {
> + DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
> + DMI_MATCH(DMI_PRODUCT_NAME, "R830"),
> + },
> + },
> + {
> + .callback = video_detect_force_native,
> + /* Toshiba Satellite/Portégé Z830 */
> + .matches = {
> + DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
> + DMI_MATCH(DMI_PRODUCT_NAME, "Z830"),
> + },
> + },
> +
> /*
> * Desktops which falsely report a backlight and which our heuristics
> * for this do not catch.