* [PATCH] Input: elan_i2c - check if device is there before really probing
@ 2017-05-04 6:29 Dmitry Torokhov
2017-05-04 6:42 ` Guenter Roeck
0 siblings, 1 reply; 5+ messages in thread
From: Dmitry Torokhov @ 2017-05-04 6:29 UTC (permalink / raw)
To: linux-input; +Cc: KT Liao, Guenter Roeck, linux-kernel
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);
+ if (error) {
+ dev_dbg(&client->dev, "nothing at this address: %d\n", error);
+ return -ENXIO;
+ }
+
/* Initialize the touchpad. */
error = elan_initialize(data);
if (error)
--
2.13.0.rc1.294.g07d810a77f-goog
--
Dmitry
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH] Input: elan_i2c - check if device is there before really probing
2017-05-04 6:29 [PATCH] Input: elan_i2c - check if device is there before really probing Dmitry Torokhov
@ 2017-05-04 6:42 ` Guenter Roeck
2017-05-08 21:10 ` Dmitry Torokhov
0 siblings, 1 reply; 5+ messages in thread
From: Guenter Roeck @ 2017-05-04 6:42 UTC (permalink / raw)
To: Dmitry Torokhov, linux-input; +Cc: KT Liao, linux-kernel
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)
>
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] Input: elan_i2c - check if device is there before really probing
2017-05-04 6:42 ` Guenter Roeck
@ 2017-05-08 21:10 ` Dmitry Torokhov
2017-05-08 21:44 ` Guenter Roeck
0 siblings, 1 reply; 5+ messages in thread
From: Dmitry Torokhov @ 2017-05-08 21:10 UTC (permalink / raw)
To: Guenter Roeck; +Cc: linux-input, KT Liao, linux-kernel
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.
--
Dmitry
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] Input: elan_i2c - check if device is there before really probing
2017-05-08 21:10 ` Dmitry Torokhov
@ 2017-05-08 21:44 ` Guenter Roeck
2017-05-08 22:47 ` Dmitry Torokhov
0 siblings, 1 reply; 5+ messages in thread
From: Guenter Roeck @ 2017-05-08 21:44 UTC (permalink / raw)
To: Dmitry Torokhov; +Cc: linux-input, KT Liao, linux-kernel
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
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] Input: elan_i2c - check if device is there before really probing
2017-05-08 21:44 ` Guenter Roeck
@ 2017-05-08 22:47 ` Dmitry Torokhov
0 siblings, 0 replies; 5+ messages in thread
From: Dmitry Torokhov @ 2017-05-08 22:47 UTC (permalink / raw)
To: Guenter Roeck; +Cc: linux-input, KT Liao, linux-kernel
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.
--
Dmitry
^ permalink raw reply [flat|nested] 5+ messages in thread
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2017-05-04 6:29 [PATCH] Input: elan_i2c - check if device is there before really probing Dmitry Torokhov
2017-05-04 6:42 ` Guenter Roeck
2017-05-08 21:10 ` Dmitry Torokhov
2017-05-08 21:44 ` Guenter Roeck
2017-05-08 22:47 ` Dmitry Torokhov
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