| Message ID | 20170504062938.GA30771@dtor-ws (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 05/03/2017 11:29 PM, Dmitry Torokhov wrote: > Before trying to properly initialize the touchpad and generate bunch of > errors, let's first see it there is anything at the given address. If we > get error, fail silently with -ENXIO. > > Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> > --- > drivers/input/mouse/elan_i2c_core.c | 9 +++++++++ > 1 file changed, 9 insertions(+) > > diff --git a/drivers/input/mouse/elan_i2c_core.c b/drivers/input/mouse/elan_i2c_core.c > index 5d3b53dd2fa2..0479730e7c5c 100644 > --- a/drivers/input/mouse/elan_i2c_core.c > +++ b/drivers/input/mouse/elan_i2c_core.c > @@ -1040,6 +1040,7 @@ static int elan_probe(struct i2c_client *client, > const struct elan_transport_ops *transport_ops; > struct device *dev = &client->dev; > struct elan_tp_data *data; > + union i2c_smbus_data dummy; > unsigned long irqflags; > int error; > > @@ -1091,6 +1092,14 @@ static int elan_probe(struct i2c_client *client, > return error; > } > > + /* Make sure there is something at this address */ > + error = i2c_smbus_xfer(client->adapter, client->addr, 0, > + I2C_SMBUS_READ, 0, I2C_SMBUS_BYTE, &dummy); Can't you just call i2c_smbus_read_byte_data(client, 0); and check if it returns an error ? Thanks, Guenter > + if (error) { > + dev_dbg(&client->dev, "nothing at this address: %d\n", error); > + return -ENXIO; > + } > + > /* Initialize the touchpad. */ > error = elan_initialize(data); > if (error) > -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Wed, May 03, 2017 at 11:42:54PM -0700, Guenter Roeck wrote: > On 05/03/2017 11:29 PM, Dmitry Torokhov wrote: > >Before trying to properly initialize the touchpad and generate bunch of > >errors, let's first see it there is anything at the given address. If we > >get error, fail silently with -ENXIO. > > > >Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> > >--- > > drivers/input/mouse/elan_i2c_core.c | 9 +++++++++ > > 1 file changed, 9 insertions(+) > > > >diff --git a/drivers/input/mouse/elan_i2c_core.c b/drivers/input/mouse/elan_i2c_core.c > >index 5d3b53dd2fa2..0479730e7c5c 100644 > >--- a/drivers/input/mouse/elan_i2c_core.c > >+++ b/drivers/input/mouse/elan_i2c_core.c > >@@ -1040,6 +1040,7 @@ static int elan_probe(struct i2c_client *client, > > const struct elan_transport_ops *transport_ops; > > struct device *dev = &client->dev; > > struct elan_tp_data *data; > >+ union i2c_smbus_data dummy; > > unsigned long irqflags; > > int error; > > > >@@ -1091,6 +1092,14 @@ static int elan_probe(struct i2c_client *client, > > return error; > > } > > > >+ /* Make sure there is something at this address */ > >+ error = i2c_smbus_xfer(client->adapter, client->addr, 0, > >+ I2C_SMBUS_READ, 0, I2C_SMBUS_BYTE, &dummy); > > Can't you just call i2c_smbus_read_byte_data(client, 0); and check if it returns > an error ? Are we guaranteed to get a result from command "0"? I am not sure, and looking at least at i2c_smbus_xfer_emulated() I2C_SMBUS_READ with I2C_SMBUS_BYTE modifier works differently form I2C_SMBUS_READ/I2C_SMBUS_BYTE_DATA (the former uses a single i2c message vs 2 for the latter). Also the form above is what i2c core uses to do detection when adapter does not implement I2C_SMBUS_QUICK, so I'd rather leave it as it was. Thanks.
On Mon, May 08, 2017 at 02:10:31PM -0700, Dmitry Torokhov wrote: > On Wed, May 03, 2017 at 11:42:54PM -0700, Guenter Roeck wrote: > > On 05/03/2017 11:29 PM, Dmitry Torokhov wrote: > > >Before trying to properly initialize the touchpad and generate bunch of > > >errors, let's first see it there is anything at the given address. If we > > >get error, fail silently with -ENXIO. > > > > > >Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> > > >--- > > > drivers/input/mouse/elan_i2c_core.c | 9 +++++++++ > > > 1 file changed, 9 insertions(+) > > > > > >diff --git a/drivers/input/mouse/elan_i2c_core.c b/drivers/input/mouse/elan_i2c_core.c > > >index 5d3b53dd2fa2..0479730e7c5c 100644 > > >--- a/drivers/input/mouse/elan_i2c_core.c > > >+++ b/drivers/input/mouse/elan_i2c_core.c > > >@@ -1040,6 +1040,7 @@ static int elan_probe(struct i2c_client *client, > > > const struct elan_transport_ops *transport_ops; > > > struct device *dev = &client->dev; > > > struct elan_tp_data *data; > > >+ union i2c_smbus_data dummy; > > > unsigned long irqflags; > > > int error; > > > > > >@@ -1091,6 +1092,14 @@ static int elan_probe(struct i2c_client *client, > > > return error; > > > } > > > > > >+ /* Make sure there is something at this address */ > > >+ error = i2c_smbus_xfer(client->adapter, client->addr, 0, > > >+ I2C_SMBUS_READ, 0, I2C_SMBUS_BYTE, &dummy); > > > > Can't you just call i2c_smbus_read_byte_data(client, 0); and check if it returns > > an error ? > > Are we guaranteed to get a result from command "0"? I am not sure, and > looking at least at i2c_smbus_xfer_emulated() I2C_SMBUS_READ with > I2C_SMBUS_BYTE modifier works differently form > I2C_SMBUS_READ/I2C_SMBUS_BYTE_DATA (the former uses a single i2c message > vs 2 for the latter). > > Also the form above is what i2c core uses to do detection when adapter > does not implement I2C_SMBUS_QUICK, so I'd rather leave it as it was. > How about i2c_smbus_read_byte() ? status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, I2C_SMBUS_READ, 0, I2C_SMBUS_BYTE, &data); return (status < 0) ? status : data.byte; Guenter -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Mon, May 08, 2017 at 02:44:25PM -0700, Guenter Roeck wrote: > On Mon, May 08, 2017 at 02:10:31PM -0700, Dmitry Torokhov wrote: > > On Wed, May 03, 2017 at 11:42:54PM -0700, Guenter Roeck wrote: > > > On 05/03/2017 11:29 PM, Dmitry Torokhov wrote: > > > >Before trying to properly initialize the touchpad and generate bunch of > > > >errors, let's first see it there is anything at the given address. If we > > > >get error, fail silently with -ENXIO. > > > > > > > >Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> > > > >--- > > > > drivers/input/mouse/elan_i2c_core.c | 9 +++++++++ > > > > 1 file changed, 9 insertions(+) > > > > > > > >diff --git a/drivers/input/mouse/elan_i2c_core.c b/drivers/input/mouse/elan_i2c_core.c > > > >index 5d3b53dd2fa2..0479730e7c5c 100644 > > > >--- a/drivers/input/mouse/elan_i2c_core.c > > > >+++ b/drivers/input/mouse/elan_i2c_core.c > > > >@@ -1040,6 +1040,7 @@ static int elan_probe(struct i2c_client *client, > > > > const struct elan_transport_ops *transport_ops; > > > > struct device *dev = &client->dev; > > > > struct elan_tp_data *data; > > > >+ union i2c_smbus_data dummy; > > > > unsigned long irqflags; > > > > int error; > > > > > > > >@@ -1091,6 +1092,14 @@ static int elan_probe(struct i2c_client *client, > > > > return error; > > > > } > > > > > > > >+ /* Make sure there is something at this address */ > > > >+ error = i2c_smbus_xfer(client->adapter, client->addr, 0, > > > >+ I2C_SMBUS_READ, 0, I2C_SMBUS_BYTE, &dummy); > > > > > > Can't you just call i2c_smbus_read_byte_data(client, 0); and check if it returns > > > an error ? > > > > Are we guaranteed to get a result from command "0"? I am not sure, and > > looking at least at i2c_smbus_xfer_emulated() I2C_SMBUS_READ with > > I2C_SMBUS_BYTE modifier works differently form > > I2C_SMBUS_READ/I2C_SMBUS_BYTE_DATA (the former uses a single i2c message > > vs 2 for the latter). > > > > Also the form above is what i2c core uses to do detection when adapter > > does not implement I2C_SMBUS_QUICK, so I'd rather leave it as it was. > > > > How about i2c_smbus_read_byte() ? > > status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, > I2C_SMBUS_READ, 0, > I2C_SMBUS_BYTE, &data); > return (status < 0) ? status : data.byte; Yeah, I think this will work. Thanks.
diff --git a/drivers/input/mouse/elan_i2c_core.c b/drivers/input/mouse/elan_i2c_core.c index 5d3b53dd2fa2..0479730e7c5c 100644 --- a/drivers/input/mouse/elan_i2c_core.c +++ b/drivers/input/mouse/elan_i2c_core.c @@ -1040,6 +1040,7 @@ static int elan_probe(struct i2c_client *client, const struct elan_transport_ops *transport_ops; struct device *dev = &client->dev; struct elan_tp_data *data; + union i2c_smbus_data dummy; unsigned long irqflags; int error; @@ -1091,6 +1092,14 @@ static int elan_probe(struct i2c_client *client, return error; } + /* Make sure there is something at this address */ + error = i2c_smbus_xfer(client->adapter, client->addr, 0, + I2C_SMBUS_READ, 0, I2C_SMBUS_BYTE, &dummy); + if (error) { + dev_dbg(&client->dev, "nothing at this address: %d\n", error); + return -ENXIO; + } + /* Initialize the touchpad. */ error = elan_initialize(data); if (error)
Before trying to properly initialize the touchpad and generate bunch of errors, let's first see it there is anything at the given address. If we get error, fail silently with -ENXIO. Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> --- drivers/input/mouse/elan_i2c_core.c | 9 +++++++++ 1 file changed, 9 insertions(+)