| Message ID | 20240711083043.8334-2-wsa+renesas@sang-engineering.com |
|---|---|
| State | Accepted |
| Delegated to: | Andi Shyti |
| Headers | show |
| Series | i2c: rcar: ensure Gen3+ reset does not disturb local targets | expand |
On Thu, Jul 11, 2024 at 10:30:44AM +0200, Wolfram Sang wrote: > R-Car Gen3+ needs a reset before every controller transfer. That erases > configuration of a potentially in parallel running local target > instance. To avoid this disruption, avoid controller transfers if a > local target is running. Also, disable SMBusHostNotify because it > requires being a controller and local target at the same time. > > Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Fixes: 3b770017b03a ("i2c: rcar: handle RXDMA HW behaviour on Gen3") > --- > drivers/i2c/busses/i2c-rcar.c | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git a/drivers/i2c/busses/i2c-rcar.c b/drivers/i2c/busses/i2c-rcar.c > index 8f2ede534f30..29cbeda59f3e 100644 > --- a/drivers/i2c/busses/i2c-rcar.c > +++ b/drivers/i2c/busses/i2c-rcar.c > @@ -884,6 +884,10 @@ static int rcar_i2c_do_reset(struct rcar_i2c_priv *priv) > { > int ret; > > + /* Don't reset if a slave instance is currently running */ > + if (priv->slave) > + return -EISCONN; > + > ret = reset_control_reset(priv->rstc); > if (ret) > return ret; > @@ -1176,6 +1180,7 @@ static int rcar_i2c_probe(struct platform_device *pdev) > if (of_property_read_bool(dev->of_node, "smbus")) > priv->flags |= ID_P_HOST_NOTIFY; > > + /* R-Car Gen3+ needs a reset before every transfer */ > if (priv->devtype >= I2C_RCAR_GEN3) { > priv->rstc = devm_reset_control_get_exclusive(&pdev->dev, NULL); > if (IS_ERR(priv->rstc)) { > @@ -1186,6 +1191,9 @@ static int rcar_i2c_probe(struct platform_device *pdev) > ret = reset_control_status(priv->rstc); > if (ret < 0) > goto out_pm_put; > + > + /* hard reset disturbs HostNotify local target, so disable it */ > + priv->flags &= ~ID_P_HOST_NOTIFY; > } > > ret = platform_get_irq(pdev, 0); > -- > 2.43.0 >
Hi Wolfram, On Thu, Jul 11, 2024 at 11:17:43PM GMT, Wolfram Sang wrote: > On Thu, Jul 11, 2024 at 10:30:44AM +0200, Wolfram Sang wrote: > > R-Car Gen3+ needs a reset before every controller transfer. That erases > > configuration of a potentially in parallel running local target > > instance. To avoid this disruption, avoid controller transfers if a > > local target is running. Also, disable SMBusHostNotify because it > > requires being a controller and local target at the same time. > > > > Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> > > Fixes: 3b770017b03a ("i2c: rcar: handle RXDMA HW behaviour on Gen3") I was about to ask. Pushed to i2c/i2c-host-fixes. Thanks, Andi
diff --git a/drivers/i2c/busses/i2c-rcar.c b/drivers/i2c/busses/i2c-rcar.c index 8f2ede534f30..29cbeda59f3e 100644 --- a/drivers/i2c/busses/i2c-rcar.c +++ b/drivers/i2c/busses/i2c-rcar.c @@ -884,6 +884,10 @@ static int rcar_i2c_do_reset(struct rcar_i2c_priv *priv) { int ret; + /* Don't reset if a slave instance is currently running */ + if (priv->slave) + return -EISCONN; + ret = reset_control_reset(priv->rstc); if (ret) return ret; @@ -1176,6 +1180,7 @@ static int rcar_i2c_probe(struct platform_device *pdev) if (of_property_read_bool(dev->of_node, "smbus")) priv->flags |= ID_P_HOST_NOTIFY; + /* R-Car Gen3+ needs a reset before every transfer */ if (priv->devtype >= I2C_RCAR_GEN3) { priv->rstc = devm_reset_control_get_exclusive(&pdev->dev, NULL); if (IS_ERR(priv->rstc)) { @@ -1186,6 +1191,9 @@ static int rcar_i2c_probe(struct platform_device *pdev) ret = reset_control_status(priv->rstc); if (ret < 0) goto out_pm_put; + + /* hard reset disturbs HostNotify local target, so disable it */ + priv->flags &= ~ID_P_HOST_NOTIFY; } ret = platform_get_irq(pdev, 0);
R-Car Gen3+ needs a reset before every controller transfer. That erases configuration of a potentially in parallel running local target instance. To avoid this disruption, avoid controller transfers if a local target is running. Also, disable SMBusHostNotify because it requires being a controller and local target at the same time. Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> --- drivers/i2c/busses/i2c-rcar.c | 8 ++++++++ 1 file changed, 8 insertions(+)