From 3aab15af9ad8fa8dc0399cb4b679d7cb85c20a56 Mon Sep 17 00:00:00 2001 From: Hans Verkuil Date: Wed, 21 Feb 2018 02:49:25 -0500 Subject: media: add tuner standby op, use where needed The v4l2_subdev core s_power op was used for two different things: power on/off sensors or video decoders/encoders and to put a tuner in standby (and only the tuner!). There is no 'tuner wakeup' op, that's done automatically when the tuner is accessed. The danger with calling (s_power, 0) to put a tuner into standby is that it is usually broadcast for all subdevs. So a video receiver subdev that supports s_power will also be powered off, and since there is no corresponding (s_power, 1) they will never be powered on again. In addition, this is specifically meant for tuners only since they draw the most current. This patch adds a new tuner op called 'standby' and replaces all calls to (core, s_power, 0) by (tuner, standby). This prevents confusion between the two uses of s_power. Note that there is no overlap: bridge drivers either just want to put the tuner into standby, or they deal with powering on/off sensors. Never both. This also makes it easier to replace s_power for the remaining bridge drivers with some PM code later. Whether we want something cleaner for tuners in the future is a separate topic. There is a lot of legacy code surrounding tuners, and I am very hesitant about making changes there. Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab --- drivers/media/usb/em28xx/em28xx-video.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'drivers/media/usb/em28xx') diff --git a/drivers/media/usb/em28xx/em28xx-video.c b/drivers/media/usb/em28xx/em28xx-video.c index f31339727d3b..d70ee13cc52e 100644 --- a/drivers/media/usb/em28xx/em28xx-video.c +++ b/drivers/media/usb/em28xx/em28xx-video.c @@ -2257,7 +2257,7 @@ static int em28xx_v4l2_close(struct file *filp) goto exit; /* Save some power by putting tuner to sleep */ - v4l2_device_call_all(&v4l2->v4l2_dev, 0, core, s_power, 0); + v4l2_device_call_all(&v4l2->v4l2_dev, 0, tuner, standby); /* do this before setting alternate! */ em28xx_set_mode(dev, EM28XX_SUSPEND); @@ -2810,7 +2810,7 @@ static int em28xx_v4l2_init(struct em28xx *dev) video_device_node_name(&v4l2->vbi_dev)); /* Save some power by putting tuner to sleep */ - v4l2_device_call_all(&v4l2->v4l2_dev, 0, core, s_power, 0); + v4l2_device_call_all(&v4l2->v4l2_dev, 0, tuner, standby); /* initialize videobuf2 stuff */ em28xx_vb2_setup(dev); -- cgit v1.2.3