[PATCH] sfc: I2C adapter initialisation fixes

[PATCH] sfc: I2C adapter initialisation fixes

[Ben Hutchings]

As recommended by Jean Delvare:
- Increase timeout to 50 ms
- Leave adapter class clear so that unwanted drivers do not probe our bus
- Use strlcpy() for name initialisation

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
---
 drivers/net/sfc/falcon.c |   12 +++---------
 1 files changed, 3 insertions(+), 9 deletions(-)

diff --git a/drivers/net/sfc/falcon.c b/drivers/net/sfc/falcon.c
index 630406e..e086100 100644
--- a/drivers/net/sfc/falcon.c
+++ b/drivers/net/sfc/falcon.c
@@ -223,13 +223,8 @@ static struct i2c_algo_bit_data falcon_i2c_bit_operations = {
 	.getsda		= falcon_getsda,
 	.getscl		= falcon_getscl,
 	.udelay		= 5,
-	/*
-	 * This is the number of system clock ticks after which
-	 * i2c-algo-bit gives up waiting for SCL to become high.
-	 * It must be at least 2 since the first tick can happen
-	 * immediately after it starts waiting.
-	 */
-	.timeout	= 2,
+	/* Wait up to 50 ms to begin command */
+	.timeout	= DIV_ROUND_UP(HZ, 20),
 };
 
 /**************************************************************************
@@ -2479,12 +2474,11 @@ int falcon_probe_nic(struct efx_nic *efx)
 
 	/* Initialise I2C adapter */
  	efx->i2c_adap.owner = THIS_MODULE;
- 	efx->i2c_adap.class = I2C_CLASS_HWMON;
 	nic_data->i2c_data = falcon_i2c_bit_operations;
 	nic_data->i2c_data.data = efx;
  	efx->i2c_adap.algo_data = &nic_data->i2c_data;
 	efx->i2c_adap.dev.parent = &efx->pci_dev->dev;
-	strcpy(efx->i2c_adap.name, "SFC4000 GPIO");
+	strlcpy(efx->i2c_adap.name, "SFC4000 GPIO", sizeof(efx->i2c_adap.name));
 	rc = i2c_bit_add_bus(&efx->i2c_adap);
 	if (rc)
 		goto fail5;

-- 
Ben Hutchings, Senior Software Engineer, Solarflare Communications
Not speaking for my employer; that's the marketing department's job.

Re: [PATCH] sfc: I2C adapter initialisation fixes

[Jean Delvare]

Hi Ben,

On Mon, 9 Jun 2008 19:25:10 +0100, Ben Hutchings wrote:
> As recommended by Jean Delvare:
> - Increase timeout to 50 ms
> - Leave adapter class clear so that unwanted drivers do not probe our bus
> - Use strlcpy() for name initialisation
> 
> Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
> ---
>  drivers/net/sfc/falcon.c |   12 +++---------
>  1 files changed, 3 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/net/sfc/falcon.c b/drivers/net/sfc/falcon.c
> index 630406e..e086100 100644
> --- a/drivers/net/sfc/falcon.c
> +++ b/drivers/net/sfc/falcon.c
> @@ -223,13 +223,8 @@ static struct i2c_algo_bit_data falcon_i2c_bit_operations = {
>  	.getsda		= falcon_getsda,
>  	.getscl		= falcon_getscl,
>  	.udelay		= 5,
> -	/*
> -	 * This is the number of system clock ticks after which
> -	 * i2c-algo-bit gives up waiting for SCL to become high.
> -	 * It must be at least 2 since the first tick can happen
> -	 * immediately after it starts waiting.
> -	 */
> -	.timeout	= 2,
> +	/* Wait up to 50 ms to begin command */

The timeout value affects every bit sent on the wire, it doesn't have
much to do with "begin command". The first half of the previous comment
was IMHO better.

> +	.timeout	= DIV_ROUND_UP(HZ, 20),
>  };
>  
>  /**************************************************************************
> @@ -2479,12 +2474,11 @@ int falcon_probe_nic(struct efx_nic *efx)
>  
>  	/* Initialise I2C adapter */
>   	efx->i2c_adap.owner = THIS_MODULE;
> - 	efx->i2c_adap.class = I2C_CLASS_HWMON;
>  	nic_data->i2c_data = falcon_i2c_bit_operations;
>  	nic_data->i2c_data.data = efx;
>   	efx->i2c_adap.algo_data = &nic_data->i2c_data;
>  	efx->i2c_adap.dev.parent = &efx->pci_dev->dev;
> -	strcpy(efx->i2c_adap.name, "SFC4000 GPIO");
> +	strlcpy(efx->i2c_adap.name, "SFC4000 GPIO", sizeof(efx->i2c_adap.name));
>  	rc = i2c_bit_add_bus(&efx->i2c_adap);
>  	if (rc)
>  		goto fail5;
> 

But other than that, patch looks good, thanks.

-- 
Jean Delvare

Re: [PATCH] sfc: I2C adapter initialisation fixes

[Jeff Garzik]

Ben Hutchings wrote:
> As recommended by Jean Delvare:
> - Increase timeout to 50 ms
> - Leave adapter class clear so that unwanted drivers do not probe our bus
> - Use strlcpy() for name initialisation
> 
> Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
> ---
>  drivers/net/sfc/falcon.c |   12 +++---------
>  1 files changed, 3 insertions(+), 9 deletions(-)

I didn't see a resend of this with Jean's requested change?

Re: [PATCH] sfc: I2C adapter initialisation fixes

[Ben Hutchings]

As recommended by Jean Delvare:
- Increase timeout to 50 ms
- Leave adapter class clear so that unwanted drivers do not probe our bus
- Use strlcpy() for name initialisation

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
diff --git a/drivers/net/sfc/falcon.c b/drivers/net/sfc/falcon.c
index 630406e..9138ee5 100644
--- a/drivers/net/sfc/falcon.c
+++ b/drivers/net/sfc/falcon.c
@@ -223,13 +223,8 @@ static struct i2c_algo_bit_data falcon_i2c_bit_operations = {
 	.getsda		= falcon_getsda,
 	.getscl		= falcon_getscl,
 	.udelay		= 5,
-	/*
-	 * This is the number of system clock ticks after which
-	 * i2c-algo-bit gives up waiting for SCL to become high.
-	 * It must be at least 2 since the first tick can happen
-	 * immediately after it starts waiting.
-	 */
-	.timeout	= 2,
+	/* Wait up to 50 ms for slave to let us pull SCL high */
+	.timeout	= DIV_ROUND_UP(HZ, 20),
 };
 
 /**************************************************************************
@@ -2479,12 +2474,11 @@ int falcon_probe_nic(struct efx_nic *efx)
 
 	/* Initialise I2C adapter */
  	efx->i2c_adap.owner = THIS_MODULE;
- 	efx->i2c_adap.class = I2C_CLASS_HWMON;
 	nic_data->i2c_data = falcon_i2c_bit_operations;
 	nic_data->i2c_data.data = efx;
  	efx->i2c_adap.algo_data = &nic_data->i2c_data;
 	efx->i2c_adap.dev.parent = &efx->pci_dev->dev;
-	strcpy(efx->i2c_adap.name, "SFC4000 GPIO");
+	strlcpy(efx->i2c_adap.name, "SFC4000 GPIO", sizeof(efx->i2c_adap.name));
 	rc = i2c_bit_add_bus(&efx->i2c_adap);
 	if (rc)
 		goto fail5;
---

I've corrected the comment about what timeout means.

Ben.

-- 
Ben Hutchings, Senior Software Engineer, Solarflare Communications
Not speaking for my employer; that's the marketing department's job.

Re: [PATCH] sfc: I2C adapter initialisation fixes

[Jean Delvare]

On Wed, 18 Jun 2008 11:58:41 +0100, Ben Hutchings wrote:
> As recommended by Jean Delvare:
> - Increase timeout to 50 ms
> - Leave adapter class clear so that unwanted drivers do not probe our bus
> - Use strlcpy() for name initialisation
> 
> Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
> diff --git a/drivers/net/sfc/falcon.c b/drivers/net/sfc/falcon.c
> index 630406e..9138ee5 100644
> --- a/drivers/net/sfc/falcon.c
> +++ b/drivers/net/sfc/falcon.c
> @@ -223,13 +223,8 @@ static struct i2c_algo_bit_data falcon_i2c_bit_operations = {
>  	.getsda		= falcon_getsda,
>  	.getscl		= falcon_getscl,
>  	.udelay		= 5,
> -	/*
> -	 * This is the number of system clock ticks after which
> -	 * i2c-algo-bit gives up waiting for SCL to become high.
> -	 * It must be at least 2 since the first tick can happen
> -	 * immediately after it starts waiting.
> -	 */
> -	.timeout	= 2,
> +	/* Wait up to 50 ms for slave to let us pull SCL high */
> +	.timeout	= DIV_ROUND_UP(HZ, 20),
>  };
>  
>  /**************************************************************************
> @@ -2479,12 +2474,11 @@ int falcon_probe_nic(struct efx_nic *efx)
>  
>  	/* Initialise I2C adapter */
>   	efx->i2c_adap.owner = THIS_MODULE;
> - 	efx->i2c_adap.class = I2C_CLASS_HWMON;
>  	nic_data->i2c_data = falcon_i2c_bit_operations;
>  	nic_data->i2c_data.data = efx;
>   	efx->i2c_adap.algo_data = &nic_data->i2c_data;
>  	efx->i2c_adap.dev.parent = &efx->pci_dev->dev;
> -	strcpy(efx->i2c_adap.name, "SFC4000 GPIO");
> +	strlcpy(efx->i2c_adap.name, "SFC4000 GPIO", sizeof(efx->i2c_adap.name));
>  	rc = i2c_bit_add_bus(&efx->i2c_adap);
>  	if (rc)
>  		goto fail5;
> ---
> 
> I've corrected the comment about what timeout means.

Thanks Ben.

Acked-by: Jean Delvare <khali@linux-fr.org>

(Technically speaking, high is the natural state of SCL, so it's pulled
down and released up - but that's nitpicking.)

-- 
Jean Delvare