Hi Wolfram,
On Thursday 03 September 2015 22:20:09 Wolfram Sang wrote:
> From: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>
>
> 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 <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>
> ---
> 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
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