Hi Wolfram, On Thursday 03 September 2015 22:20:09 Wolfram Sang wrote: > From: Wolfram Sang <[email protected]> > > Setting up new messages was done in process context while handling a > message was in interrupt context. Because of the HW design, this IP core > is sensitive to timing, so the context switches were too expensive. Move > this setup to interrupt context as well. > > In my test setup, this fixed the occasional 'data byte sent twice' issue > which a number of people have seen. It also fixes to send REP_START > after a read message which was wrongly send as a STOP + START sequence > before.
I'm afraid this patch has been found by git bisect to break HDMI on Koelsch :-( The regmap_read(adv7511->regmap, ADV7511_REG_CHIP_REVISION, &val) call in drivers/gpu/drm/i2c/adv7511.c returns -ENXIO. Reverting the patch on top of Geert's current drivers master branch fixes the problem. > Signed-off-by: Wolfram Sang <[email protected]> > --- > drivers/i2c/busses/i2c-rcar.c | 74 +++++++++++++++++++--------------------- > 1 file changed, 37 insertions(+), 37 deletions(-) > > diff --git a/drivers/i2c/busses/i2c-rcar.c b/drivers/i2c/busses/i2c-rcar.c > index 6e459a338ccc75..36c79301044b71 100644 > --- a/drivers/i2c/busses/i2c-rcar.c > +++ b/drivers/i2c/busses/i2c-rcar.c > @@ -266,6 +266,13 @@ static void rcar_i2c_prepare_msg(struct rcar_i2c_priv > *priv) rcar_i2c_write(priv, ICMIER, read ? RCAR_IRQ_RECV : RCAR_IRQ_SEND); > } > > +static void rcar_i2c_next_msg(struct rcar_i2c_priv *priv) > +{ > + priv->msg++; > + priv->msgs_left--; > + rcar_i2c_prepare_msg(priv); > +} > + > /* > * interrupt functions > */ > @@ -308,21 +315,17 @@ static int rcar_i2c_irq_send(struct rcar_i2c_priv > *priv, u32 msr) * [ICRXTX] -> [SHIFT] -> [I2C bus] > */ > > - if (priv->flags & ID_LAST_MSG) > + if (priv->flags & ID_LAST_MSG) { > /* > * If current msg is the _LAST_ msg, > * prepare stop condition here. > * ID_DONE will be set on STOP irq. > */ > rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_STOP); > - else > - /* > - * If current msg is _NOT_ last msg, > - * it doesn't call stop phase. > - * thus, there is no STOP irq. > - * return ID_DONE here. > - */ > - return ID_DONE; > + } else { > + rcar_i2c_next_msg(priv); > + return 0; > + } > } > > rcar_i2c_write(priv, ICMSR, RCAR_IRQ_ACK_SEND); > @@ -366,7 +369,10 @@ static int rcar_i2c_irq_recv(struct rcar_i2c_priv > *priv, u32 msr) else > rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_DATA); > > - rcar_i2c_write(priv, ICMSR, RCAR_IRQ_ACK_RECV); > + if (priv->pos == msg->len && !(priv->flags & ID_LAST_MSG)) > + rcar_i2c_next_msg(priv); > + else > + rcar_i2c_write(priv, ICMSR, RCAR_IRQ_ACK_RECV); > > return 0; > } > @@ -461,6 +467,7 @@ static irqreturn_t rcar_i2c_irq(int irq, void *ptr) > > /* Stop */ > if (msr & MST) { > + priv->msgs_left--; /* The last message also made it */ > rcar_i2c_flags_set(priv, ID_DONE); > goto out; > } > @@ -500,35 +507,28 @@ static int rcar_i2c_master_xfer(struct i2c_adapter > *adap, /* This HW can't send STOP after address phase */ > if (msgs[i].len == 0) { > ret = -EOPNOTSUPP; > - break; > - } > - > - /* init each data */ > - priv->msg = &msgs[i]; > - priv->msgs_left = num - i; > - > - rcar_i2c_prepare_msg(priv); > - > - time_left = wait_event_timeout(priv->wait, > - rcar_i2c_flags_has(priv, ID_DONE), > - adap->timeout); > - if (!time_left) { > - rcar_i2c_init(priv); > - ret = -ETIMEDOUT; > - break; > - } > - > - if (rcar_i2c_flags_has(priv, ID_NACK)) { > - ret = -ENXIO; > - break; > - } > - > - if (rcar_i2c_flags_has(priv, ID_ARBLOST)) { > - ret = -EAGAIN; > - break; > + goto out; > } > + } > > - ret = i + 1; /* The number of transfer */ > + /* init data */ > + priv->msg = msgs; > + priv->msgs_left = num; > + > + rcar_i2c_prepare_msg(priv); > + > + time_left = wait_event_timeout(priv->wait, > + rcar_i2c_flags_has(priv, ID_DONE), > + num * adap->timeout); > + if (!time_left) { > + rcar_i2c_init(priv); > + ret = -ETIMEDOUT; > + } else if (rcar_i2c_flags_has(priv, ID_NACK)) { > + ret = -ENXIO; > + } else if (rcar_i2c_flags_has(priv, ID_ARBLOST)) { > + ret = -EAGAIN; > + } else { > + ret = num - priv->msgs_left; /* The number of transfer */ > } > out: > pm_runtime_put(dev); -- Regards, Laurent Pinchart -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
