lkml.org 
[lkml]   [2018]   [Apr]   [8]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH AUTOSEL for 4.9 141/293] media: dvb-frontends/cxd2841er: require STATE_ACTIVE_* for agc readout
    Date
    From: Daniel Scheller <d.scheller@gmx.net>

    [ Upstream commit 8982735f8dd02096b75255e3c0a0df28aeaa9955 ]

    When the demod driver puts the demod into sleep or shutdown state and it's
    status is then polled e.g. via "dvb-fe-tool -m", i2c errors are printed
    to the kernel log. If the last delsys was DVB-T/T2:

    cxd2841er: i2c wr failed=-5 addr=6c reg=00 len=1
    cxd2841er: i2c rd failed=-5 addr=6c reg=26

    and if it was DVB-C:

    cxd2841er: i2c wr failed=-5 addr=6c reg=00 len=1
    cxd2841er: i2c rd failed=-5 addr=6c reg=49

    This happens when read_status unconditionally calls into the
    read_signal_strength() function which triggers the read_agc_gain_*()
    functions, where these registered are polled.

    This isn't a critical thing since when the demod is active again, no more
    such errors are logged, however this might make users suspecting defects.

    Fix this by requiring STATE_ACTIVE_* in priv->state. If it isn't in any
    active state, additionally set the strength scale to NOT_AVAILABLE.

    Signed-off-by: Daniel Scheller <d.scheller@gmx.net>
    Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
    Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
    ---
    drivers/media/dvb-frontends/cxd2841er.c | 5 ++++-
    1 file changed, 4 insertions(+), 1 deletion(-)

    diff --git a/drivers/media/dvb-frontends/cxd2841er.c b/drivers/media/dvb-frontends/cxd2841er.c
    index b97647cd7dc6..8c175d959038 100644
    --- a/drivers/media/dvb-frontends/cxd2841er.c
    +++ b/drivers/media/dvb-frontends/cxd2841er.c
    @@ -3210,7 +3210,10 @@ static int cxd2841er_get_frontend(struct dvb_frontend *fe,
    else if (priv->state == STATE_ACTIVE_TC)
    cxd2841er_read_status_tc(fe, &status);

    - cxd2841er_read_signal_strength(fe);
    + if (priv->state == STATE_ACTIVE_TC || priv->state == STATE_ACTIVE_S)
    + cxd2841er_read_signal_strength(fe);
    + else
    + p->strength.stat[0].scale = FE_SCALE_NOT_AVAILABLE;

    if (status & FE_HAS_LOCK) {
    cxd2841er_read_snr(fe);
    --
    2.15.1
    \
     
     \ /
      Last update: 2018-04-09 04:17    [W:4.050 / U:0.036 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site