Em Wed, 19 Apr 2017 15:23:39 +0200 Pavel Machek <pa...@ucw.cz> escreveu:
> Hi! > > > As warned by kbuild test robot: > > warning: (VIDEO_EM28XX_V4L2) selects VIDEO_OV2640 which has unmet > > direct dependencies (MEDIA_SUPPORT && VIDEO_V4L2 && I2C && GPIOLIB && > > MEDIA_CAMERA_SUPPORT) > > > > The em28xx driver can use ov2640, but it doesn't depend > > (or use) the GPIOLIB in order to power off/on the sensor. > > > > So, as we want to allow both usages with and without > > GPIOLIB, make its dependency optional. > > Umm. The driver will not work too well with sensor powered off, no? > Will this result in some tricky-to-debug situations? > > > config VIDEO_OV2640 > > tristate "OmniVision OV2640 sensor support" > > - depends on VIDEO_V4L2 && I2C && GPIOLIB > > + depends on VIDEO_V4L2 && I2C > > depends on MEDIA_CAMERA_SUPPORT > > help > > This is a Video4Linux2 sensor-level driver for the > > OmniVision > > Better solution would be for VIDEO_EM28XX_V4L2 to depend on GPIOLIB, > too, no? If not, should there be BUG_ON(priv->pwdn_gpio); > BUG_ON(priv->resetb_gpio);? Pavel, The em28xx driver was added upstream several years the gpio driver. It controls GPIO using a different logic. It makes no sense to make it dependent on GPIOLIB, except if someone converts it to use it. Besides that, I won't doubt that, at least on some em28xx webcams, the sensor is always on. Converting it to use the gpiolib not an easy task, as it supports a hundred different device models and several different types of devices: webcams, analog TV, digital TV, hybrid devices (plus devices with FM radio too). Too much work for no gain and a high risk of regressions. Thanks, Mauro
