On Thursday 11 June 2015 14:29:24 Hans de Goede wrote: > Hi, > > 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@xxxxxxxxxx> > >>--- > >> 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... > > Regards, > > Hans 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 my Acked-By. Once you will create new patches for backlight (maybe for intel i915), please CC me, so I can discuss about them too. -- Pali Rohár pali.rohar@xxxxxxxxx -- To unsubscribe from this list: send the line "unsubscribe platform-driver-x86" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
