[PATCH 1/2] platform/chrome: cros_ec_proto: Update feature check

[PATCH 1/2] platform/chrome: cros_ec_proto: Update feature check

[Prashant Malani]

EC feature flags now require more than 32 bits to be represented. In
order to make cros_ec_check_features() usable for more recent features,
update it to account for the extra 32 bits of features.

Signed-off-by: Prashant Malani <pmalani@chromium.org>
---
 drivers/platform/chrome/cros_ec_proto.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/platform/chrome/cros_ec_proto.c b/drivers/platform/chrome/cros_ec_proto.c
index a7404d69b2d3..772edad80593 100644
--- a/drivers/platform/chrome/cros_ec_proto.c
+++ b/drivers/platform/chrome/cros_ec_proto.c
@@ -813,6 +813,7 @@ EXPORT_SYMBOL(cros_ec_get_host_event);
 int cros_ec_check_features(struct cros_ec_dev *ec, int feature)
 {
 	struct cros_ec_command *msg;
+	u32 mask;
 	int ret;
 
 	if (ec->features[0] == -1U && ec->features[1] == -1U) {
@@ -839,7 +840,12 @@ int cros_ec_check_features(struct cros_ec_dev *ec, int feature)
 		kfree(msg);
 	}
 
-	return ec->features[feature / 32] & EC_FEATURE_MASK_0(feature);
+	if (feature >= 32)
+		mask = EC_FEATURE_MASK_1(feature);
+	else
+		mask = EC_FEATURE_MASK_0(feature);
+
+	return ec->features[feature / 32] & mask;
 }
 EXPORT_SYMBOL_GPL(cros_ec_check_features);
 
-- 
2.32.0.554.ge1b32706d8-goog

[PATCH 2/2] platform/chrome: cros_ec_typec: Use existing feature check

[Prashant Malani]

Replace the cros_typec_feature_supported() function with the
pre-existing cros_ec_check_features() function which does the same
thing.

Signed-off-by: Prashant Malani <pmalani@chromium.org>
---
 drivers/platform/chrome/cros_ec_typec.c | 33 +++++++++----------------
 1 file changed, 11 insertions(+), 22 deletions(-)

diff --git a/drivers/platform/chrome/cros_ec_typec.c b/drivers/platform/chrome/cros_ec_typec.c
index 27c068c4c38d..f96af8aa31b5 100644
--- a/drivers/platform/chrome/cros_ec_typec.c
+++ b/drivers/platform/chrome/cros_ec_typec.c
@@ -1054,24 +1054,6 @@ static int cros_typec_get_cmd_version(struct cros_typec_data *typec)
 	return 0;
 }
 
-/* Check the EC feature flags to see if TYPEC_* features are supported. */
-static int cros_typec_feature_supported(struct cros_typec_data *typec, enum ec_feature_code feature)
-{
-	struct ec_response_get_features resp = {};
-	int ret;
-
-	ret = cros_typec_ec_command(typec, 0, EC_CMD_GET_FEATURES, NULL, 0,
-				    &resp, sizeof(resp));
-	if (ret < 0) {
-		dev_warn(typec->dev,
-			 "Failed to get features, assuming typec feature=%d unsupported.\n",
-			 feature);
-		return 0;
-	}
-
-	return resp.flags[feature / 32] & EC_FEATURE_MASK_1(feature);
-}
-
 static void cros_typec_port_work(struct work_struct *work)
 {
 	struct cros_typec_data *typec = container_of(work, struct cros_typec_data, port_work);
@@ -1113,6 +1095,7 @@ MODULE_DEVICE_TABLE(of, cros_typec_of_match);
 
 static int cros_typec_probe(struct platform_device *pdev)
 {
+	struct cros_ec_dev *ec_dev = NULL;
 	struct device *dev = &pdev->dev;
 	struct cros_typec_data *typec;
 	struct ec_response_usb_pd_ports resp;
@@ -1132,10 +1115,16 @@ static int cros_typec_probe(struct platform_device *pdev)
 		return ret;
 	}
 
-	typec->typec_cmd_supported = !!cros_typec_feature_supported(typec,
-					EC_FEATURE_TYPEC_CMD);
-	typec->needs_mux_ack = !!cros_typec_feature_supported(typec,
-					EC_FEATURE_TYPEC_MUX_REQUIRE_AP_ACK);
+	if (typec->ec->ec)
+		ec_dev = dev_get_drvdata(&typec->ec->ec->dev);
+
+	if (ec_dev) {
+		typec->typec_cmd_supported = !!cros_ec_check_features(ec_dev, EC_FEATURE_TYPEC_CMD);
+		typec->needs_mux_ack = !!cros_ec_check_features(ec_dev,
+							EC_FEATURE_TYPEC_MUX_REQUIRE_AP_ACK);
+	} else {
+		dev_warn(dev, "Invalid cros_ec_dev pointer; feature flags not checked.\n");
+	}
 
 	ret = cros_typec_ec_command(typec, 0, EC_CMD_USB_PD_PORTS, NULL, 0,
 				    &resp, sizeof(resp));
-- 
2.32.0.554.ge1b32706d8-goog

Re: [PATCH 2/2] platform/chrome: cros_ec_typec: Use existing feature check

[Enric Balletbo i Serra]

Hi Prashant,

Thank you for your patch.

On 2/8/21 20:47, Prashant Malani wrote:
> Replace the cros_typec_feature_supported() function with the
> pre-existing cros_ec_check_features() function which does the same
> thing.
> 
> Signed-off-by: Prashant Malani <pmalani@chromium.org>
> ---
>  drivers/platform/chrome/cros_ec_typec.c | 33 +++++++++----------------
>  1 file changed, 11 insertions(+), 22 deletions(-)
> 
> diff --git a/drivers/platform/chrome/cros_ec_typec.c b/drivers/platform/chrome/cros_ec_typec.c
> index 27c068c4c38d..f96af8aa31b5 100644
> --- a/drivers/platform/chrome/cros_ec_typec.c
> +++ b/drivers/platform/chrome/cros_ec_typec.c
> @@ -1054,24 +1054,6 @@ static int cros_typec_get_cmd_version(struct cros_typec_data *typec)
>  	return 0;
>  }
>  
> -/* Check the EC feature flags to see if TYPEC_* features are supported. */
> -static int cros_typec_feature_supported(struct cros_typec_data *typec, enum ec_feature_code feature)
> -{
> -	struct ec_response_get_features resp = {};
> -	int ret;
> -
> -	ret = cros_typec_ec_command(typec, 0, EC_CMD_GET_FEATURES, NULL, 0,
> -				    &resp, sizeof(resp));
> -	if (ret < 0) {
> -		dev_warn(typec->dev,
> -			 "Failed to get features, assuming typec feature=%d unsupported.\n",
> -			 feature);
> -		return 0;
> -	}
> -
> -	return resp.flags[feature / 32] & EC_FEATURE_MASK_1(feature);
> -}
> -
>  static void cros_typec_port_work(struct work_struct *work)
>  {
>  	struct cros_typec_data *typec = container_of(work, struct cros_typec_data, port_work);
> @@ -1113,6 +1095,7 @@ MODULE_DEVICE_TABLE(of, cros_typec_of_match);
>  
>  static int cros_typec_probe(struct platform_device *pdev)
>  {
> +	struct cros_ec_dev *ec_dev = NULL;
>  	struct device *dev = &pdev->dev;
>  	struct cros_typec_data *typec;
>  	struct ec_response_usb_pd_ports resp;
> @@ -1132,10 +1115,16 @@ static int cros_typec_probe(struct platform_device *pdev)
>  		return ret;
>  	}
>  
> -	typec->typec_cmd_supported = !!cros_typec_feature_supported(typec,
> -					EC_FEATURE_TYPEC_CMD);
> -	typec->needs_mux_ack = !!cros_typec_feature_supported(typec,
> -					EC_FEATURE_TYPEC_MUX_REQUIRE_AP_ACK);
> +	if (typec->ec->ec)

Is this check really needed. Can typec->ec->ec be NULL at this point?

> +		ec_dev = dev_get_drvdata(&typec->ec->ec->dev);
> +
> +	if (ec_dev) {

and this?

> +		typec->typec_cmd_supported = !!cros_ec_check_features(ec_dev, EC_FEATURE_TYPEC_CMD);
> +		typec->needs_mux_ack = !!cros_ec_check_features(ec_dev,
> +							EC_FEATURE_TYPEC_MUX_REQUIRE_AP_ACK);
> +	} else {

and this?

> +		dev_warn(dev, "Invalid cros_ec_dev pointer; feature flags not checked.\n");

Can't just be

		typec->typec_cmd_supported = !!cros_ec_check_features(ec_dev,
EC_FEATURE_TYPEC_CMD);
		typec->needs_mux_ack = !!cros_ec_check_features(ec_dev,
EC_FEATURE_TYPEC_MUX_REQUIRE_AP_ACK);

Thanks,
 Enric

> +	}
>  
>  	ret = cros_typec_ec_command(typec, 0, EC_CMD_USB_PD_PORTS, NULL, 0,
>  				    &resp, sizeof(resp));
> 

Re: [PATCH 2/2] platform/chrome: cros_ec_typec: Use existing feature check

[Prashant Malani]

Hi Enric,

Thanks for reviewing the patch.

On Tue, Aug 03, 2021 at 12:09:47PM +0200, Enric Balletbo i Serra wrote:
> Hi Prashant,
> 
> Thank you for your patch.
> 
> On 2/8/21 20:47, Prashant Malani wrote:
> > Replace the cros_typec_feature_supported() function with the
> > pre-existing cros_ec_check_features() function which does the same
> > thing.
> > 
> > Signed-off-by: Prashant Malani <pmalani@chromium.org>
> > ---
> >  drivers/platform/chrome/cros_ec_typec.c | 33 +++++++++----------------
> >  1 file changed, 11 insertions(+), 22 deletions(-)
> > 
> > diff --git a/drivers/platform/chrome/cros_ec_typec.c b/drivers/platform/chrome/cros_ec_typec.c
> > index 27c068c4c38d..f96af8aa31b5 100644
> > --- a/drivers/platform/chrome/cros_ec_typec.c
> > +++ b/drivers/platform/chrome/cros_ec_typec.c
> > @@ -1054,24 +1054,6 @@ static int cros_typec_get_cmd_version(struct cros_typec_data *typec)
> >  	return 0;
> >  }
> >  
> > -/* Check the EC feature flags to see if TYPEC_* features are supported. */
> > -static int cros_typec_feature_supported(struct cros_typec_data *typec, enum ec_feature_code feature)
> > -{
> > -	struct ec_response_get_features resp = {};
> > -	int ret;
> > -
> > -	ret = cros_typec_ec_command(typec, 0, EC_CMD_GET_FEATURES, NULL, 0,
> > -				    &resp, sizeof(resp));
> > -	if (ret < 0) {
> > -		dev_warn(typec->dev,
> > -			 "Failed to get features, assuming typec feature=%d unsupported.\n",
> > -			 feature);
> > -		return 0;
> > -	}
> > -
> > -	return resp.flags[feature / 32] & EC_FEATURE_MASK_1(feature);
> > -}
> > -
> >  static void cros_typec_port_work(struct work_struct *work)
> >  {
> >  	struct cros_typec_data *typec = container_of(work, struct cros_typec_data, port_work);
> > @@ -1113,6 +1095,7 @@ MODULE_DEVICE_TABLE(of, cros_typec_of_match);
> >  
> >  static int cros_typec_probe(struct platform_device *pdev)
> >  {
> > +	struct cros_ec_dev *ec_dev = NULL;
> >  	struct device *dev = &pdev->dev;
> >  	struct cros_typec_data *typec;
> >  	struct ec_response_usb_pd_ports resp;
> > @@ -1132,10 +1115,16 @@ static int cros_typec_probe(struct platform_device *pdev)
> >  		return ret;
> >  	}
> >  
> > -	typec->typec_cmd_supported = !!cros_typec_feature_supported(typec,
> > -					EC_FEATURE_TYPEC_CMD);
> > -	typec->needs_mux_ack = !!cros_typec_feature_supported(typec,
> > -					EC_FEATURE_TYPEC_MUX_REQUIRE_AP_ACK);
> > +	if (typec->ec->ec)
> 
> Is this check really needed. Can typec->ec->ec be NULL at this point?

Looking at it closely, it looks like it can't be NULL
(cros_ec_register() fails if the platform device registration fails).

> 
> > +		ec_dev = dev_get_drvdata(&typec->ec->ec->dev);
> > +
> > +	if (ec_dev) {
> 
> and this?

I haven't been able to prove this solely by looking at the code, hence
wanted to be defensive here. That said, in the ARM and x86 platforms I
tested this change on, it wasn't NULL.

> 
> > +		typec->typec_cmd_supported = !!cros_ec_check_features(ec_dev, EC_FEATURE_TYPEC_CMD);
> > +		typec->needs_mux_ack = !!cros_ec_check_features(ec_dev,
> > +							EC_FEATURE_TYPEC_MUX_REQUIRE_AP_ACK);
> > +	} else {
> 
> and this?
> 
> > +		dev_warn(dev, "Invalid cros_ec_dev pointer; feature flags not checked.\n");
> 
> Can't just be
> 
> 		typec->typec_cmd_supported = !!cros_ec_check_features(ec_dev,
> EC_FEATURE_TYPEC_CMD);
> 		typec->needs_mux_ack = !!cros_ec_check_features(ec_dev,
> EC_FEATURE_TYPEC_MUX_REQUIRE_AP_ACK);

Sure; I'll push another version with the NULL checks dropped.

Thanks,

-Prashant

Re: [PATCH 1/2] platform/chrome: cros_ec_proto: Update feature check

[Benson Leung]

[-- Attachment #1: Type: text/plain, Size: 1629 bytes --]

Hi Prashant,

On Mon, Aug 02, 2021 at 11:47:10AM -0700, Prashant Malani wrote:
> EC feature flags now require more than 32 bits to be represented. In
> order to make cros_ec_check_features() usable for more recent features,
> update it to account for the extra 32 bits of features.
> 
> Signed-off-by: Prashant Malani <pmalani@chromium.org>

FYI, as discussed, this patch was dropped from the series.

> ---
>  drivers/platform/chrome/cros_ec_proto.c | 8 +++++++-
>  1 file changed, 7 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/platform/chrome/cros_ec_proto.c b/drivers/platform/chrome/cros_ec_proto.c
> index a7404d69b2d3..772edad80593 100644
> --- a/drivers/platform/chrome/cros_ec_proto.c
> +++ b/drivers/platform/chrome/cros_ec_proto.c
> @@ -813,6 +813,7 @@ EXPORT_SYMBOL(cros_ec_get_host_event);
>  int cros_ec_check_features(struct cros_ec_dev *ec, int feature)
>  {
>  	struct cros_ec_command *msg;
> +	u32 mask;
>  	int ret;
>  
>  	if (ec->features[0] == -1U && ec->features[1] == -1U) {
> @@ -839,7 +840,12 @@ int cros_ec_check_features(struct cros_ec_dev *ec, int feature)
>  		kfree(msg);
>  	}
>  
> -	return ec->features[feature / 32] & EC_FEATURE_MASK_0(feature);
> +	if (feature >= 32)
> +		mask = EC_FEATURE_MASK_1(feature);
> +	else
> +		mask = EC_FEATURE_MASK_0(feature);
> +
> +	return ec->features[feature / 32] & mask;
>  }
>  EXPORT_SYMBOL_GPL(cros_ec_check_features);
>  
> -- 
> 2.32.0.554.ge1b32706d8-goog
> 

-- 
Benson Leung
Staff Software Engineer
Chrome OS Kernel
Google Inc.
bleung@google.com
Chromium OS Project
bleung@chromium.org

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