From c8382c8e3295a1c85975c1898410f4d103650e4a Mon Sep 17 00:00:00 2001 From: Manu Abraham Date: Sat, 13 Feb 2010 17:06:14 -0300 Subject: [PATCH] V4L/DVB: stv090x: Add some notes about the internal tuner I/O control Signed-off-by: Manu Abraham Signed-off-by: Mauro Carvalho Chehab --- drivers/media/dvb/frontends/stv090x.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/media/dvb/frontends/stv090x.c b/drivers/media/dvb/frontends/stv090x.c index a461fdff2c9c..425e7a43ae19 100644 --- a/drivers/media/dvb/frontends/stv090x.c +++ b/drivers/media/dvb/frontends/stv090x.c @@ -758,6 +758,15 @@ static int stv090x_i2c_gate_ctrl(struct stv090x_state *state, int enable) { u32 reg; + /* + * NOTE! A lock is used as a FSM to control the state in which + * access is serialized between two tuners on the same demod. + * This has nothing to do with a lock to protect a critical section + * which may in some other cases be confused with protecting I/O + * access to the demodulator gate. + * In case of any error, the lock is unlocked and exit within the + * relevant operations themselves. + */ if (enable) mutex_lock(&state->internal->tuner_lock); -- 2.20.1