[Letux-kernel] [Staff] USB udc problem with 4.5-rc

[H. Nikolaus Schaller]

Am 10.03.2016 um 17:53 schrieb H. Nikolaus Schaller <hns at goldelico.com>:

> Hi Lukas,
> 
>> Am 10.03.2016 um 17:08 schrieb Lukas Maerdian <lukas at goldelico.com>:
>> 
>> Hi,
>> 
>> I did rebase my android kernel tree to letux-base (4.5-rc7) today.
>> Unfortunately quite some stuff seems to be broken, so I only get access
>> via the serial console.
> 
> :(
> 
>> 
>> Most importantly the FunctionFS (used to access the device via USB/ADB)
>> is not working. Whenever I try to restart the adb daemon on the GTA04 I
>> can see the following error:
>> 
>> root at android:/ # restart adbd
>> root at android:/ # [  665.916717] read descriptors
>> [  665.920257] read strings
>> [  665.923217] udc-core: couldn't find an available UDC - added [g_ffs]
>> to list of pending drivers
> 
> Hm.
> 
>> 
>> This message comes from a change, which was introduced into the USB
>> gadget subsystem during the 4.5 merge window and changes the UDC and
>> Gadget registration process:
>> https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/drivers/usb/gadget/udc/udc-core.c?id=855ed04a3758b205e84b269f92d26ab36ed8e2f7
>> 
>> It does not find any USB Device Controller (UDC), when loading the
>> FunctionFS. What is the UDC used on our OMAP3?
> 
> I don't know... Even I don't know what UDC is...

It looks as if it tries to manage the loading sequence of driver modules.
For USB core and for gadget modules.

Interestingly for me the g_ether isn't working any more although it worked for
4.5-rc4 or so. But it may be a problem of my host setup.

If I connect to my eeePC it seems to show up on lsusb. And there are messages
from g_ether.

> 
>> And is there a driver for
>> it? I found an "omap_udc" driver in drivers/usb/gadget/udc, but this
>> seems to be for OMAP1 only.
> 
> How did that work on the 4.4 kernel?
> 
>> 
>> Other than that the backlight driver is not working, too, even though
>> the pwm_bl and pwm_omap_dmtimer modules are loaded. Are you aware of any
>> relevant changes in the PWM subsystem?
> 
> No, it should work out of the box. It may be necessary to load some more
> kernel modules.
> 
> I will boot my GTA04 and send the lsmod asap.

Here it is:

root at letux:~# uname -a
Linux letux 4.5.0-rc7-letux+ #2159 SMP Wed Mar 9 08:25:01 CET 2016 armv7l GNU/Linux
root at letux:~# lsmod
Module                  Size  Used by
bluetooth             381564  4 
autofs4                25916  1 
usb_f_ecm               7039  1 
g_ether                 4993  0 
usb_f_rndis            16962  2 g_ether
u_ether                13270  3 usb_f_ecm,usb_f_rndis,g_ether
libcomposite           43892  3 usb_f_ecm,usb_f_rndis,g_ether
configfs               29192  4 usb_f_ecm,usb_f_rndis,libcomposite
ipv6                  410330  20 
bq27xxx_battery         9282  0 
hso                    30144  0 
omapdrm                65445  2 
drm_kms_helper        123949  1 omapdrm
cfbfillrect             3744  1 drm_kms_helper
syscopyarea             3005  1 drm_kms_helper
cfbimgblt               2378  1 drm_kms_helper
sysfillrect             3744  1 drm_kms_helper
sysimgblt               2619  1 drm_kms_helper
fb_sys_fops             1703  1 drm_kms_helper
cfbcopyarea             3005  1 drm_kms_helper
drm                   323918  4 drm_kms_helper,omapdrm
panel_tpo_td028ttec1     5318  1 
w2sg0004                5680  0 
w2cbw003_bluetooth      2177  0 
snd_soc_simple_card     7166  0 
snd_soc_omap_twl4030     7429  0 
w1_bq27000              1635  0 
encoder_opa362          3378  1 
twl4030_madc_hwmon      3361  0 
wwan_on_off             5371  0 
pwm_omap_dmtimer        4003  1 
connector_analog_tv     3566  1 
pwm_bl                  4573  0 
twl4030_madc_battery     3998  0 
extcon_gpio             3185  0 
omap_hdq                6595  0 
omap2430                8104  0 
snd_soc_omap_mcbsp     18229  2 
snd_soc_omap            3291  1 snd_soc_omap_mcbsp
snd_pcm_dmaengine       5616  1 snd_soc_omap
bmp085_i2c              1706  0 
itg3200                 4789  1 
hmc5843_i2c             3258  0 
at24                    5541  0 
leds_tca6507            6574  1 
lis3lv02d_i2c           3673  0 
phy_twl4030_usb         8970  3 
hmc5843_core            6842  1 hmc5843_i2c
bma150                  6740  0 
lis3lv02d              15911  1 lis3lv02d_i2c
tsc2007                 7831  0 
input_polldev           4917  2 bma150,lis3lv02d
musb_hdrc              74592  2 omap2430,phy_twl4030_usb
gpio_twl4030            4789  0 
rtc_twl                 6128  0 
twl4030_pwrbutton       2333  0 
twl4030_madc            9490  1 twl4030_madc_hwmon
twl4030_vibra           2853  0 
twl4030_charger         9283  0 
snd_soc_twl4030        47855  1 
ehci_omap               3307  0 
omapdss               285702  6 panel_tpo_td028ttec1,connector_analog_tv,omapdrm,encoder_opa362
root at letux:~#