I posted this on the alsa-user list, but did not get a reply.
Although it occasionally works, I am usually unable to get any sound out of the speakers on a dell latitude e7240 using alsa-1.0.28 and linux-3.16.6 - see details at the end of the post.
If so, Windows or BIOS is the problem. It doesn't set up the pin configuration properly Linux driver relies on.
I just updated the bios to the latest version, but no change :(
I'd rather patch my current kernel if possible - do you know where the EPAD control patch is by any chance?
Look through git log of sound/pci/hda/patch_realtek.c. But beware that
the patches won't be applied cleanly; otherwise I would have marked them for stable.
But I'll ask for testing with the newer kernels in anyway if patching
fails, so...
Thanks
The first hunk of the patch applies cleanly, but...
CC [M] sound/pci/hda/patch_realtek.o sound/pci/hda/patch_realtek.c: In function 'alc_fill_eapd_coef': sound/pci/hda/patch_realtek.c:234:2: error: implicit declaration of function 'alc_get_coef0' [-Werror=implicit-function-declaration] coef = alc_get_coef0(codec); ^ sound/pci/hda/patch_realtek.c:238:2: error: implicit declaration of function 'alc_update_coef_idx' [-Werror=implicit-function-declaration] alc_update_coef_idx(codec, 0x7, 0, 1<<5); ^ sound/pci/hda/patch_realtek.c: At top level: sound/pci/hda/patch_realtek.c:695:21: error: conflicting types for 'alc_get_coef0' static unsigned int alc_get_coef0(struct hda_codec *codec) ^ sound/pci/hda/patch_realtek.c:234:9: note: previous implicit declaration of 'alc_get_coef0' was here coef = alc_get_coef0(codec); ^ sound/pci/hda/patch_realtek.c:230:13: warning: 'alc_fill_eapd_coef' defined but not used [-Wunused-function] static void alc_fill_eapd_coef(struct hda_codec *codec) ^ cc1: warning: unrecognized command line option "-Wno-errors" cc1: some warnings being treated as errors scripts/Makefile.build:257: recipe for target 'sound/pci/hda/patch_realtek.o' failed make[1]: *** [sound/pci/hda/patch_realtek.o] Error 1 Makefile:1333: recipe for target '_module_sound/pci/hda' failed make: *** [_module_sound/pci/hda] Error 2