[PATCH 19/32] dell-laptop: Port to new backlight interface selection API
pali.rohar at gmail.com
Thu Jun 11 06:06:31 PDT 2015
On Thursday 11 June 2015 14:29:24 Hans de Goede wrote:
> On 11-06-15 13:47, Pali Rohár wrote:
> >On Wednesday 10 June 2015 15:01:19 Hans de Goede wrote:
> >>Port the backlight selection logic to the new backlight interface
> >>selection API.
> >>Signed-off-by: Hans de Goede <hdegoede at redhat.com>
> >> drivers/platform/x86/dell-laptop.c | 6 ++----
> >> 1 file changed, 2 insertions(+), 4 deletions(-)
> >>diff --git a/drivers/platform/x86/dell-laptop.c b/drivers/platform/x86/dell-laptop.c
> >>index d688d80..db2e031 100644
> >>--- a/drivers/platform/x86/dell-laptop.c
> >>+++ b/drivers/platform/x86/dell-laptop.c
> >>@@ -31,6 +31,7 @@
> >> #include <linux/slab.h>
> >> #include <linux/debugfs.h>
> >> #include <linux/seq_file.h>
> >>+#include <acpi/video.h>
> >> #include "../../firmware/dcdbas.h"
> >> #define BRIGHTNESS_TOKEN 0x7d
> >>@@ -1921,10 +1922,7 @@ static int __init dell_init(void)
> >> &dell_debugfs_fops);
> >> #ifdef CONFIG_ACPI
> >>- /* In the event of an ACPI backlight being available, don't
> >>- * register the platform controller.
> >>- */
> >>- if (acpi_video_backlight_support())
> >>+ if (acpi_video_get_backlight_type() != acpi_backlight_vendor)
> >> return 0;
> >> #endif
> >Now I'm thinking... Is this correct condition? And do we need it? This
> >Dell backlight interface works even if ACPI or intel i915 driver
> >controls backlight. Why we should prevent dell-laptop.ko to register
> >Dell backlight interface if ACPI video already register one? And why not
> >prevent when intel i915 driver register another?
> 3 things:
> 1) This is mostly a cleanup series, it does not make any behavioral
> changes (other then renaming the kernelcmdline option and we've
> already discussed fixing that).
> 2) All 3 drivers ultimately bit-bang the same hardware, we really should
> have only one driver banging the hardware, so
> if (acpi_video_get_backlight_type() != acpi_backlight_vendor)
> return 0;
> Definitely is the right thing todo here.
> 3) You're right that the intel_backlight still registering even if
> acpi_video_get_backlight_type() != acpi_backlight_native is weird, but
> that is how it was before this series, and userspace prefers firmware
> type backlight sysfs entries over platform /raw ones so it will
> automatically pick the right one. We should consider not registering
> the backlight sysfs class interface from the intel code when
> acpi_video_get_backlight_type() != acpi_backlight_native but that is
> something for later...
Ok. This patch series is just refactor/cleanup which does not change
functional behavior. I'm ok with this dell-laptop change, so you can add
Once you will create new patches for backlight (maybe for intel i915),
please CC me, so I can discuss about them too.
pali.rohar at gmail.com
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