[Letux-kernel] FYI: backlight pwm issues

Lukas Maerdian lukas at goldelico.com
Sat May 21 15:30:49 CEST 2016


Hi!

are those pwm/backlight issues still valid for 4.6-rc7?
I rebased the work/lukas/android branch to letux-base (4.6-rc7) today
and now have the problem that the screen is turned off completely...

I think that the pwm/backlight drivers are the culprit, as
/sys/class/backlight/ is empty. The modules (pwm_bl and
pwm_omap_dmtimer) are loaded, but interestingly pwm_omap_dmtimer is not
used by any module (whereas it should be used by pwm_bl...):

pwm_bl 3930 0 - Live 0x00000000
pwm_omap_dmtimer 3597 0 - Live 0x00000000

Also I was not able to activate the BL via its GPIO. This command
returns -1 and the 'value' file is still set to 0:

root at android:/ #  echo 1 > /sys/class/gpio/gpio57/value

Are there some recent changes to the backlight drivers I need to know
of? Or do you have any other idea of what could be the problem here?

BR,
  Lukas


Full lsmod:

root at android:/ # lsmod

rtc_twl 4734 0 - Live 0x00000000
gpio_twl4030 4058 0 - Live 0x00000000
extcon_gpio 2627 0 - Live 0x00000000
bma150 5498 0 - Live 0x00000000
lis3lv02d_i2c 3042 0 - Live 0x00000000
lis3lv02d 13075 1 lis3lv02d_i2c, Live 0x00000000
input_polldev 3473 2 bma150,lis3lv02d, Live 0x00000000
hmc5843_i2c 2566 0 - Live 0x00000000
hmc5843_core 5415 1 hmc5843_i2c, Live 0x00000000
itg3200 3907 1 - Live 0x00000000
ehci_omap 2895 0 - Live 0x00000000
libertas 96291 0 - Live 0x00000000
cfg80211 500482 1 libertas, Live 0x00000000
leds_tca6507 5318 0 - Live 0x00000000
hci_uart 13298 0 - Live 0x00000000
bluetooth 317593 1 hci_uart, Live 0x00000000
iptable_nat 1494 1 - Live 0x00000000
nf_conntrack_ipv4 12429 1 - Live 0x00000000
nf_defrag_ipv4 1290 1 nf_conntrack_ipv4, Live 0x00000000
nf_nat_ipv4 4483 1 iptable_nat, Live 0x00000000
nf_nat 12743 1 nf_nat_ipv4, Live 0x00000000
nf_conntrack 101882 3 nf_conntrack_ipv4,nf_nat_ipv4,nf_nat, Live 0x00000000
twl4030_vibra 2340 0 - Live 0x00000000
g_ffs 2843 1 - Live 0x00000000
ip6table_mangle 1543 1 - Live 0x00000000
omap2430 6795 0 - Live 0x00000000
iptable_mangle 1412 1 - Live 0x00000000
twl4030_pwrbutton 1950 0 - Live 0x00000000
bq27xxx_battery 6876 0 - Live 0x00000000
ip6table_raw 1214 1 - Live 0x00000000
w1_bq27000 1151 0 - Live 0x00000000
iptable_raw 1275 1 - Live 0x00000000
omap_hdq 5338 0 - Live 0x00000000
twl4030_charger 8059 0 - Live 0x00000000
phy_twl4030_usb 7239 3 - Live 0x00000000
musb_hdrc 61424 2 omap2430,phy_twl4030_usb, Live 0x00000000
tsc2007 4222 0 - Live 0x00000000
pwm_bl 3930 0 - Live 0x00000000
pwm_omap_dmtimer 3597 0 - Live 0x00000000
snd_soc_omap_mcbsp 15408 2 - Live 0x00000000
snd_soc_omap 2743 1 snd_soc_omap_mcbsp, Live 0x00000000
snd_pcm_dmaengine 3612 1 snd_soc_omap, Live 0x00000000
snd_soc_omap_twl4030 6752 0 - Live 0x00000000
snd_soc_simple_card 5969 0 - Live 0x00000000
ip6table_filter 1328 1 - Live 0x00000000
snd_soc_twl4030 41381 1 - Live 0x00000000
ip6_tables 10384 3 ip6table_mangle,ip6table_raw,ip6table_filter, Live
0x00000000
ipv6 365928 13 ip6table_mangle,[permanent], Live 0x00000000
omapdrm 55793 2 - Live 0x00000000
drm_kms_helper 89714 1 omapdrm, Live 0x00000000
cfbcopyarea 2803 1 drm_kms_helper, Live 0x00000000
sysimgblt 1973 1 drm_kms_helper, Live 0x00000000
sysfillrect 3135 1 drm_kms_helper, Live 0x00000000
iptable_filter 1388 1 - Live 0x00000000
cfbimgblt 2037 1 drm_kms_helper, Live 0x00000000
syscopyarea 2867 1 drm_kms_helper, Live 0x00000000
cfbfillrect 3199 1 drm_kms_helper, Live 0x00000000
fb_sys_fops 1461 1 drm_kms_helper, Live 0x00000000
drm 248029 3 omapdrm,drm_kms_helper, Live 0x00000000
ip_tables 10189 4 iptable_nat,iptable_mangle,iptable_raw,iptable_filter,
Live 0x00000000
x_tables 11636 8
ip6table_mangle,iptable_mangle,ip6table_raw,iptable_raw,ip6table_filter,ip6_tables,iptable_filter,ip_tables,
Live 0x00000000
panel_tpo_td028ttec1 4487 1 - Live 0x00000000
omapdss 184617 3 omapdrm,panel_tpo_td028ttec1, Live 0x00000000
usb_f_fs 20546 3 g_ffs, Live 0x00000000
libcomposite 33022 2 g_ffs,usb_f_fs, Live 0x00000000
configfs 22622 3 usb_f_fs,libcomposite, Live 0x00000000


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