diff mbox series

[RFC,2/2] tpm: tpm_tis: Provide error messages in tpm_tis_core_init

Message ID 20240906060947.4844-3-wahrenst@gmx.net (mailing list archive)
State New
Headers show
Series tpm: Minor improvements | expand

Commit Message

Stefan Wahren Sept. 6, 2024, 6:09 a.m. UTC 
In case of SPI wiring issues (e.g. MISO pin permanent high) the
core init won't provide any error message on failure. Add some
helpful error messages to tpm_tis_core_init(), which helps
to better understand why the driver won't probe.

Signed-off-by: Stefan Wahren <wahrenst@gmx.net>
---
 drivers/char/tpm/tpm_tis_core.c | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

--
2.34.1

Comments

Jarkko Sakkinen Sept. 6, 2024, 9:50 a.m. UTC | #1 
On Fri Sep 6, 2024 at 9:09 AM EEST, Stefan Wahren wrote:
> In case of SPI wiring issues (e.g. MISO pin permanent high) the
> core init won't provide any error message on failure. Add some
> helpful error messages to tpm_tis_core_init(), which helps
> to better understand why the driver won't probe.
>
> Signed-off-by: Stefan Wahren <wahrenst@gmx.net>
> ---
>  drivers/char/tpm/tpm_tis_core.c | 15 ++++++++++++---
>  1 file changed, 12 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
> index fdef214b9f6b..830e331fcebe 100644
> --- a/drivers/char/tpm/tpm_tis_core.c
> +++ b/drivers/char/tpm/tpm_tis_core.c
> @@ -1133,8 +1133,10 @@ int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,
>  	dev_set_drvdata(&chip->dev, priv);
>
>  	rc = tpm_tis_read32(priv, TPM_DID_VID(0), &vendor);
> -	if (rc < 0)
> +	if (rc < 0) {
> +		dev_err(dev, "Failed to read TPM_DID_VID register: %d\n", rc);
>  		return rc;
> +	}
>
>  	priv->manufacturer_id = vendor;
>
> @@ -1162,19 +1164,25 @@ int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,
>  		chip->ops->clk_enable(chip, true);
>
>  	if (wait_startup(chip, 0) != 0) {
> +		dev_err(dev, "TPM device not accessible (0x%0x)\n",
> +			vendor);
>  		rc = -ENODEV;
>  		goto out_err;
>  	}
>
>  	/* Take control of the TPM's interrupt hardware and shut it off */
>  	rc = tpm_tis_read32(priv, TPM_INT_ENABLE(priv->locality), &intmask);
> -	if (rc < 0)
> +	if (rc < 0) {
> +		dev_err(dev, "Failed to read TPM_INT_ENABLE register: %d\n", rc);
>  		goto out_err;
> +	}
>
>  	/* Figure out the capabilities */
>  	rc = tpm_tis_read32(priv, TPM_INTF_CAPS(priv->locality), &intfcaps);
> -	if (rc < 0)
> +	if (rc < 0) {
> +		dev_err(dev, "Failed to read TPM_INTF_CAPS register: %d\n", rc);
>  		goto out_err;
> +	}
>
>  	dev_dbg(dev, "TPM interface capabilities (0x%x):\n",
>  		intfcaps);
> @@ -1209,6 +1217,7 @@ int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,
>
>  	rc = tpm_tis_request_locality(chip, 0);
>  	if (rc < 0) {
> +		dev_err(dev, "Failed to request locality (0x%0x)\n", vendor);
>  		rc = -ENODEV;
>  		goto out_err;
>  	}
> --
> 2.34.1

No thanks. It not only adds helpful messages but has potential to add
unwanted merge conflicts.

BR, Jarkko
Stefan Wahren Sept. 6, 2024, 2:42 p.m. UTC | #2 
Am 06.09.24 um 11:50 schrieb Jarkko Sakkinen:
> On Fri Sep 6, 2024 at 9:09 AM EEST, Stefan Wahren wrote:
>> In case of SPI wiring issues (e.g. MISO pin permanent high) the
>> core init won't provide any error message on failure. Add some
>> helpful error messages to tpm_tis_core_init(), which helps
>> to better understand why the driver won't probe.
>>
>> Signed-off-by: Stefan Wahren <wahrenst@gmx.net>
>> ---
>>   drivers/char/tpm/tpm_tis_core.c | 15 ++++++++++++---
>>   1 file changed, 12 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
>> index fdef214b9f6b..830e331fcebe 100644
>> --- a/drivers/char/tpm/tpm_tis_core.c
>> +++ b/drivers/char/tpm/tpm_tis_core.c
>> @@ -1133,8 +1133,10 @@ int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,
>>   	dev_set_drvdata(&chip->dev, priv);
>>
>>   	rc = tpm_tis_read32(priv, TPM_DID_VID(0), &vendor);
>> -	if (rc < 0)
>> +	if (rc < 0) {
>> +		dev_err(dev, "Failed to read TPM_DID_VID register: %d\n", rc);
>>   		return rc;
>> +	}
>>
>>   	priv->manufacturer_id = vendor;
>>
>> @@ -1162,19 +1164,25 @@ int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,
>>   		chip->ops->clk_enable(chip, true);
>>
>>   	if (wait_startup(chip, 0) != 0) {
>> +		dev_err(dev, "TPM device not accessible (0x%0x)\n",
>> +			vendor);
>>   		rc = -ENODEV;
>>   		goto out_err;
>>   	}
>>
>>   	/* Take control of the TPM's interrupt hardware and shut it off */
>>   	rc = tpm_tis_read32(priv, TPM_INT_ENABLE(priv->locality), &intmask);
>> -	if (rc < 0)
>> +	if (rc < 0) {
>> +		dev_err(dev, "Failed to read TPM_INT_ENABLE register: %d\n", rc);
>>   		goto out_err;
>> +	}
>>
>>   	/* Figure out the capabilities */
>>   	rc = tpm_tis_read32(priv, TPM_INTF_CAPS(priv->locality), &intfcaps);
>> -	if (rc < 0)
>> +	if (rc < 0) {
>> +		dev_err(dev, "Failed to read TPM_INTF_CAPS register: %d\n", rc);
>>   		goto out_err;
>> +	}
>>
>>   	dev_dbg(dev, "TPM interface capabilities (0x%x):\n",
>>   		intfcaps);
>> @@ -1209,6 +1217,7 @@ int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,
>>
>>   	rc = tpm_tis_request_locality(chip, 0);
>>   	if (rc < 0) {
>> +		dev_err(dev, "Failed to request locality (0x%0x)\n", vendor);
>>   		rc = -ENODEV;
>>   		goto out_err;
>>   	}
>> --
>> 2.34.1
> No thanks. It not only adds helpful messages but has potential to add
> unwanted merge conflicts.
So this is a general NAK?

So with every setup where the driver exits without an error message, the
developer should add its own debug?
>
> BR, Jarkko
diff mbox series

Patch

diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
index fdef214b9f6b..830e331fcebe 100644
--- a/drivers/char/tpm/tpm_tis_core.c
+++ b/drivers/char/tpm/tpm_tis_core.c
@@ -1133,8 +1133,10 @@  int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,
 	dev_set_drvdata(&chip->dev, priv);

 	rc = tpm_tis_read32(priv, TPM_DID_VID(0), &vendor);
-	if (rc < 0)
+	if (rc < 0) {
+		dev_err(dev, "Failed to read TPM_DID_VID register: %d\n", rc);
 		return rc;
+	}

 	priv->manufacturer_id = vendor;

@@ -1162,19 +1164,25 @@  int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,
 		chip->ops->clk_enable(chip, true);

 	if (wait_startup(chip, 0) != 0) {
+		dev_err(dev, "TPM device not accessible (0x%0x)\n",
+			vendor);
 		rc = -ENODEV;
 		goto out_err;
 	}

 	/* Take control of the TPM's interrupt hardware and shut it off */
 	rc = tpm_tis_read32(priv, TPM_INT_ENABLE(priv->locality), &intmask);
-	if (rc < 0)
+	if (rc < 0) {
+		dev_err(dev, "Failed to read TPM_INT_ENABLE register: %d\n", rc);
 		goto out_err;
+	}

 	/* Figure out the capabilities */
 	rc = tpm_tis_read32(priv, TPM_INTF_CAPS(priv->locality), &intfcaps);
-	if (rc < 0)
+	if (rc < 0) {
+		dev_err(dev, "Failed to read TPM_INTF_CAPS register: %d\n", rc);
 		goto out_err;
+	}

 	dev_dbg(dev, "TPM interface capabilities (0x%x):\n",
 		intfcaps);
@@ -1209,6 +1217,7 @@  int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,

 	rc = tpm_tis_request_locality(chip, 0);
 	if (rc < 0) {
+		dev_err(dev, "Failed to request locality (0x%0x)\n", vendor);
 		rc = -ENODEV;
 		goto out_err;
 	}