From f23b7952d37c69c0caa6c8dfb85dbf2eb9e5fcaa Mon Sep 17 00:00:00 2001 From: Andy Walls Date: Sun, 5 Dec 2010 19:42:30 -0300 Subject: [PATCH] [media] cx25840: Prevent device probe failure due to volume control ERANGE error This patch fixes a regression that crept into 2.6.36. The volume control scale in the cx25840 driver has an unusual mapping from register values to v4l2 volume control values. Enforce the mapping limits, so that the default volume control setting does not fall out of bounds to prevent the cx25840 module device probe from failing. Signed-off-by: Andy Walls Cc: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab --- drivers/media/video/cx25840/cx25840-core.c | 19 +++++++++++++++++-- 1 file changed, 17 insertions(+), 2 deletions(-) diff --git a/drivers/media/video/cx25840/cx25840-core.c b/drivers/media/video/cx25840/cx25840-core.c index dfb198d0415b..f16461844c5c 100644 --- a/drivers/media/video/cx25840/cx25840-core.c +++ b/drivers/media/video/cx25840/cx25840-core.c @@ -1989,8 +1989,23 @@ static int cx25840_probe(struct i2c_client *client, v4l2_ctrl_new_std(&state->hdl, &cx25840_ctrl_ops, V4L2_CID_HUE, -128, 127, 1, 0); if (!is_cx2583x(state)) { - default_volume = 228 - cx25840_read(client, 0x8d4); - default_volume = ((default_volume / 2) + 23) << 9; + default_volume = cx25840_read(client, 0x8d4); + /* + * Enforce the legacy PVR-350/MSP3400 to PVR-150/CX25843 volume + * scale mapping limits to avoid -ERANGE errors when + * initializing the volume control + */ + if (default_volume > 228) { + /* Bottom out at -96 dB, v4l2 vol range 0x2e00-0x2fff */ + default_volume = 228; + cx25840_write(client, 0x8d4, 228); + } + else if (default_volume < 20) { + /* Top out at + 8 dB, v4l2 vol range 0xfe00-0xffff */ + default_volume = 20; + cx25840_write(client, 0x8d4, 20); + } + default_volume = (((228 - default_volume) >> 1) + 23) << 9; state->volume = v4l2_ctrl_new_std(&state->hdl, &cx25840_audio_ctrl_ops, V4L2_CID_AUDIO_VOLUME, -- 2.30.2