Alex, > I tested the patches with the following setup. Please note I tested > the microphone mute led by GUI, as the hotkey does not work on this > system. Thank you for taking the time to test this series, it is appreciated. I would not expect the switching method (GUI/hotkey) to matter here, as long as we can compare behavior of two kernel versions by consistently using one of them. > > 1. Downloaded the below patches from patchwork > > 9518737 Awaiting Upstream [v2,1/6] dell-led: remove GUID check from > dell_micmute_led_set() > 9518761 Awaiting Upstream [v2,2/6] ALSA: hda - use > dell_micmute_led_set() instead of dell_app_wmi_led_set() > 9518741 Awaiting Upstream [v2,3/6] ALSA: hda - rename > dell_led_set_func to dell_micmute_led_set_func > 9518725 Awaiting Upstream [v2,4/6] platform/x86: dell-laptop: import > dell_micmute_led_set() from drivers/leds/dell-led.c > 9518727 Awaiting Upstream [v2,5/6] dell-led: remove code related to mic mute LED > 9518735 Awaiting Upstream [v2,6/6] dell-led: move driver to > drivers/platform/x86/dell-wmi-led.c > 9520053 Awaiting Upstream [v2,6+/6] platform/x86: dell-wmi-led: fix > coding style issues > > 2. Installed Ubuntu 16.10 (Linux kernel 4.8) on Dell Latitude 7180 Just to be sure, I assume you meant 7280? > > -> Microphone mute led works as expected > > 3. Applied downloaded patches to kernel 4.8 without any conflicts, but > kernel will not compile successfully. I am confused. This patch series should apply cleanly to 4.9 and its surroundings. Between 4.8 and 4.9, commit 4875a5f72180 ("ALSA: hda - Fix a failure of micmute led when having multi adcs") happened. This makes it impossible to apply this patch series cleanly on top of 4.8 without reducing context to one line. Moreover, I applied this patch series (with reduced context) to 4.8 and successfully compiled the kernel. Could you shed some light on where exactly did your build crash? > > 4. Installed Ubuntu Zesty kernel (Linux kernel 4.9) > > -> Microphone mute led works as expected > > 5. Applied and compiled downloaded patches to kernel 4.9 > > -> Microphone mute led does not work Any chance of a git bisect? > > 6. Compiled and installed Linux kernel 4.10 rc8 > > -> Microphone mute led does not work This is even more confusing. Between 4.9, which you claim works fine, and 4.10-rc8, which you claim does not work, I can see no changes to either drivers/leds/dell-led.c or sound/pci/hda/dell_wmi_helper.c. Kernel configuration issue? > > 7. Applied and compiled downloaded patches to kernel 4.10 rc8 > > -> Microphone mute led does not work No surprises here if it really does not work with 4.10-rc8. -- Best regards, Michał Kępień