Hello. +static int omap34xxcam_open(struct inode *inode, struct file *file) +{ <snip> + if (atomic_inc_return(&vdev->users) == 1) { + isp_get(); + if (omap34xxcam_slave_power_set(vdev, V4L2_POWER_ON, + OMAP34XXCAM_SLAVE_POWER_ALL)) + goto out_slave_power_set_standby; + omap34xxcam_slave_power_set( + vdev, V4L2_POWER_STANDBY, + OMAP34XXCAM_SLAVE_POWER_SENSOR); + omap34xxcam_slave_power_suggest( + vdev, V4L2_POWER_STANDBY, + OMAP34XXCAM_SLAVE_POWER_LENS); + } I'm wondering whether this V4L2_POWER_STANDBY operation for sensor device is really necessary. Because if that makes sensor device in standby mode, we do S_FMT and bunch of V4L2 APIs while the camera module is in standby mode. In most cases of "sensor + ISP" SOC camera modules, I2C command is not working while the camera module is in standby mode. Following the camera interface source code, sensor goes down to standby mode until VIDIOC_STREAMON is called. If this power up timing depends on sensor device, then I think we need a conditional power on sequence. As you defined slave devices as SENSOR, LENS, FLASH, then how about making a new slave category like "ISP" for "sensor+ISP" SOC modules? Then we could make slave devices with conditional cases. Cheers. Regards, Nate -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html