diff mbox series

[1/2] HID: uclogic: Store firmware name in params

Message ID 20240321144553.262409-2-jose.exposito89@gmail.com (mailing list archive)
State Superseded
Delegated to: Jiri Kosina
Headers show
Series Expose firmware name to identify tablets in libwacom | expand

Commit Message

José Expósito March 21, 2024, 2:38 p.m. UTC 
A future patch will need to access the firmware name to expose it to
userspace via sysfs.

Store it in `uclogic_params->fw_name`.

Signed-off-by: José Expósito <jose.exposito89@gmail.com>
---
 drivers/hid/hid-uclogic-params.c | 14 +++++++-------
 drivers/hid/hid-uclogic-params.h |  5 +++++
 2 files changed, 12 insertions(+), 7 deletions(-)

Comments

Benjamin Tissoires March 21, 2024, 3:01 p.m. UTC | #1 
Hi José,

On Mar 21 2024, José Expósito wrote:
> A future patch will need to access the firmware name to expose it to
> userspace via sysfs.
> 
> Store it in `uclogic_params->fw_name`.
> 
> Signed-off-by: José Expósito <jose.exposito89@gmail.com>
> ---
>  drivers/hid/hid-uclogic-params.c | 14 +++++++-------
>  drivers/hid/hid-uclogic-params.h |  5 +++++
>  2 files changed, 12 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/hid/hid-uclogic-params.c b/drivers/hid/hid-uclogic-params.c
> index 9859dad36495..79ec3eb80f84 100644
> --- a/drivers/hid/hid-uclogic-params.c
> +++ b/drivers/hid/hid-uclogic-params.c
> @@ -121,6 +121,7 @@ void uclogic_params_hid_dbg(const struct hid_device *hdev,
>  		params->invalid ? "true" : "false");
>  	hid_dbg(hdev, ".desc_ptr = %p\n", params->desc_ptr);
>  	hid_dbg(hdev, ".desc_size = %u\n", params->desc_size);
> +	hid_dbg(hdev, ".fw_name = %s\n", params->fw_name);
>  	hid_dbg(hdev, ".pen = {\n");
>  	uclogic_params_pen_hid_dbg(hdev, &params->pen);
>  	hid_dbg(hdev, "\t}\n");
> @@ -652,6 +653,7 @@ void uclogic_params_cleanup(struct uclogic_params *params)
>  	if (!params->invalid) {
>  		size_t i;
>  		kfree(params->desc_ptr);
> +		kfree(params->fw_name);
>  		uclogic_params_pen_cleanup(&params->pen);
>  		for (i = 0; i < ARRAY_SIZE(params->frame_list); i++)
>  			uclogic_params_frame_cleanup(&params->frame_list[i]);
> @@ -837,7 +839,6 @@ static int uclogic_params_huion_init(struct uclogic_params *params,
>  	/* The resulting parameters (noop) */
>  	struct uclogic_params p = {0, };
>  	static const char transition_ver[] = "HUION_T153_160607";
> -	char *ver_ptr = NULL;
>  	const size_t ver_len = sizeof(transition_ver) + 1;
>  	__u8 *params_ptr = NULL;
>  	size_t params_len = 0;
> @@ -870,14 +871,14 @@ static int uclogic_params_huion_init(struct uclogic_params *params,
>  	}
>  
>  	/* Try to get firmware version */
> -	ver_ptr = kzalloc(ver_len, GFP_KERNEL);
> -	if (ver_ptr == NULL) {
> +	p.fw_name = kzalloc(ver_len, GFP_KERNEL);
> +	if (!p.fw_name) {
>  		rc = -ENOMEM;
>  		goto cleanup;
>  	}
> -	rc = usb_string(udev, 201, ver_ptr, ver_len);
> +	rc = usb_string(udev, 201, p.fw_name, ver_len);
>  	if (rc == -EPIPE) {
> -		*ver_ptr = '\0';
> +		*p.fw_name = '\0';
>  	} else if (rc < 0) {
>  		hid_err(hdev,
>  			"failed retrieving Huion firmware version: %d\n", rc);
> @@ -885,7 +886,7 @@ static int uclogic_params_huion_init(struct uclogic_params *params,
>  	}
>  
>  	/* If this is a transition firmware */
> -	if (strcmp(ver_ptr, transition_ver) == 0) {
> +	if (strcmp(p.fw_name, transition_ver) == 0) {
>  		hid_dbg(hdev,
>  			"transition firmware detected, not probing pen v2 parameters\n");
>  	} else {
> @@ -1028,7 +1029,6 @@ static int uclogic_params_huion_init(struct uclogic_params *params,
>  	rc = 0;
>  cleanup:
>  	kfree(params_ptr);
> -	kfree(ver_ptr);
>  	uclogic_params_cleanup(&p);
>  	return rc;
>  }
> diff --git a/drivers/hid/hid-uclogic-params.h b/drivers/hid/hid-uclogic-params.h
> index d6ffadb2f601..412c916770f5 100644
> --- a/drivers/hid/hid-uclogic-params.h
> +++ b/drivers/hid/hid-uclogic-params.h
> @@ -232,6 +232,11 @@ struct uclogic_params {
>  	 * List of event hooks.
>  	 */
>  	struct uclogic_raw_event_hook *event_hooks;
> +	/*
> +	 * Firmware name, exposed to userspace via sysfs as it is used to
> +	 * identify the tablet.
> +	 */
> +	char *fw_name;

I can't remember if this was on the table or not, but any reasons to not
use hid->uniq[64] field instead of a custom sysfs?
If there is already a value, we could just append the firmware version
with a colon (:) separator.

The main reason would be to not export a new sysfs specifically for this
driver, but it would also allow HID-BPF to have access to the value and
thus allow to detect if the device works with the given bpf program.

Cheers,
Benjamin

>  };
>  
>  /* Driver data */
> -- 
> 2.44.0
>
José Expósito March 22, 2024, 10:06 a.m. UTC | #2 
Hi Benjamin,

Thanks a lot for the quick review :)

On Thu, Mar 21, 2024 at 04:01:06PM +0100, Benjamin Tissoires wrote:
> 
> Hi José,
> 
> On Mar 21 2024, José Expósito wrote:
> > A future patch will need to access the firmware name to expose it to
> > userspace via sysfs.
> > 
> > Store it in `uclogic_params->fw_name`.
> > 
> > Signed-off-by: José Expósito <jose.exposito89@gmail.com>
> > ---
> >  drivers/hid/hid-uclogic-params.c | 14 +++++++-------
> >  drivers/hid/hid-uclogic-params.h |  5 +++++
> >  2 files changed, 12 insertions(+), 7 deletions(-)
> > 
> > diff --git a/drivers/hid/hid-uclogic-params.c b/drivers/hid/hid-uclogic-params.c
> > index 9859dad36495..79ec3eb80f84 100644
> > --- a/drivers/hid/hid-uclogic-params.c
> > +++ b/drivers/hid/hid-uclogic-params.c
> > @@ -121,6 +121,7 @@ void uclogic_params_hid_dbg(const struct hid_device *hdev,
> >  		params->invalid ? "true" : "false");
> >  	hid_dbg(hdev, ".desc_ptr = %p\n", params->desc_ptr);
> >  	hid_dbg(hdev, ".desc_size = %u\n", params->desc_size);
> > +	hid_dbg(hdev, ".fw_name = %s\n", params->fw_name);
> >  	hid_dbg(hdev, ".pen = {\n");
> >  	uclogic_params_pen_hid_dbg(hdev, &params->pen);
> >  	hid_dbg(hdev, "\t}\n");
> > @@ -652,6 +653,7 @@ void uclogic_params_cleanup(struct uclogic_params *params)
> >  	if (!params->invalid) {
> >  		size_t i;
> >  		kfree(params->desc_ptr);
> > +		kfree(params->fw_name);
> >  		uclogic_params_pen_cleanup(&params->pen);
> >  		for (i = 0; i < ARRAY_SIZE(params->frame_list); i++)
> >  			uclogic_params_frame_cleanup(&params->frame_list[i]);
> > @@ -837,7 +839,6 @@ static int uclogic_params_huion_init(struct uclogic_params *params,
> >  	/* The resulting parameters (noop) */
> >  	struct uclogic_params p = {0, };
> >  	static const char transition_ver[] = "HUION_T153_160607";
> > -	char *ver_ptr = NULL;
> >  	const size_t ver_len = sizeof(transition_ver) + 1;
> >  	__u8 *params_ptr = NULL;
> >  	size_t params_len = 0;
> > @@ -870,14 +871,14 @@ static int uclogic_params_huion_init(struct uclogic_params *params,
> >  	}
> >  
> >  	/* Try to get firmware version */
> > -	ver_ptr = kzalloc(ver_len, GFP_KERNEL);
> > -	if (ver_ptr == NULL) {
> > +	p.fw_name = kzalloc(ver_len, GFP_KERNEL);
> > +	if (!p.fw_name) {
> >  		rc = -ENOMEM;
> >  		goto cleanup;
> >  	}
> > -	rc = usb_string(udev, 201, ver_ptr, ver_len);
> > +	rc = usb_string(udev, 201, p.fw_name, ver_len);
> >  	if (rc == -EPIPE) {
> > -		*ver_ptr = '\0';
> > +		*p.fw_name = '\0';
> >  	} else if (rc < 0) {
> >  		hid_err(hdev,
> >  			"failed retrieving Huion firmware version: %d\n", rc);
> > @@ -885,7 +886,7 @@ static int uclogic_params_huion_init(struct uclogic_params *params,
> >  	}
> >  
> >  	/* If this is a transition firmware */
> > -	if (strcmp(ver_ptr, transition_ver) == 0) {
> > +	if (strcmp(p.fw_name, transition_ver) == 0) {
> >  		hid_dbg(hdev,
> >  			"transition firmware detected, not probing pen v2 parameters\n");
> >  	} else {
> > @@ -1028,7 +1029,6 @@ static int uclogic_params_huion_init(struct uclogic_params *params,
> >  	rc = 0;
> >  cleanup:
> >  	kfree(params_ptr);
> > -	kfree(ver_ptr);
> >  	uclogic_params_cleanup(&p);
> >  	return rc;
> >  }
> > diff --git a/drivers/hid/hid-uclogic-params.h b/drivers/hid/hid-uclogic-params.h
> > index d6ffadb2f601..412c916770f5 100644
> > --- a/drivers/hid/hid-uclogic-params.h
> > +++ b/drivers/hid/hid-uclogic-params.h
> > @@ -232,6 +232,11 @@ struct uclogic_params {
> >  	 * List of event hooks.
> >  	 */
> >  	struct uclogic_raw_event_hook *event_hooks;
> > +	/*
> > +	 * Firmware name, exposed to userspace via sysfs as it is used to
> > +	 * identify the tablet.
> > +	 */
> > +	char *fw_name;
> 
> I can't remember if this was on the table or not, but any reasons to not
> use hid->uniq[64] field instead of a custom sysfs?
> If there is already a value, we could just append the firmware version
> with a colon (:) separator.
> 
> The main reason would be to not export a new sysfs specifically for this
> driver, but it would also allow HID-BPF to have access to the value and
> thus allow to detect if the device works with the given bpf program.

That's a very good point.

I tested with some tablets and for HUION, the uniq field is empty.
Other vendors just put garbage there. In fact, we override it in
tablets with battery to avoid a crash [1].

So, it'll be fine to just override the garbage in that field with
an actual unique ID. Sent v2 with the sugested change [2].

Thanks,
Jose

[1] https://github.com/JoseExposito/linux/commit/9845a1304a06805c3193c58283ca428c32c14fa7#diff-b3e9836cea703e50e8febb1f09b86f92833200e7bda4c9c1ea5a1d8b569b01dbR1257-R1262
[2] https://lore.kernel.org/linux-input/20240322100210.107152-1-jose.exposito89@gmail.com/T/

> Cheers,
> Benjamin
> 
> >  };
> >  
> >  /* Driver data */
> > -- 
> > 2.44.0
> >
diff mbox series

Patch

diff --git a/drivers/hid/hid-uclogic-params.c b/drivers/hid/hid-uclogic-params.c
index 9859dad36495..79ec3eb80f84 100644
--- a/drivers/hid/hid-uclogic-params.c
+++ b/drivers/hid/hid-uclogic-params.c
@@ -121,6 +121,7 @@  void uclogic_params_hid_dbg(const struct hid_device *hdev,
 		params->invalid ? "true" : "false");
 	hid_dbg(hdev, ".desc_ptr = %p\n", params->desc_ptr);
 	hid_dbg(hdev, ".desc_size = %u\n", params->desc_size);
+	hid_dbg(hdev, ".fw_name = %s\n", params->fw_name);
 	hid_dbg(hdev, ".pen = {\n");
 	uclogic_params_pen_hid_dbg(hdev, &params->pen);
 	hid_dbg(hdev, "\t}\n");
@@ -652,6 +653,7 @@  void uclogic_params_cleanup(struct uclogic_params *params)
 	if (!params->invalid) {
 		size_t i;
 		kfree(params->desc_ptr);
+		kfree(params->fw_name);
 		uclogic_params_pen_cleanup(&params->pen);
 		for (i = 0; i < ARRAY_SIZE(params->frame_list); i++)
 			uclogic_params_frame_cleanup(&params->frame_list[i]);
@@ -837,7 +839,6 @@  static int uclogic_params_huion_init(struct uclogic_params *params,
 	/* The resulting parameters (noop) */
 	struct uclogic_params p = {0, };
 	static const char transition_ver[] = "HUION_T153_160607";
-	char *ver_ptr = NULL;
 	const size_t ver_len = sizeof(transition_ver) + 1;
 	__u8 *params_ptr = NULL;
 	size_t params_len = 0;
@@ -870,14 +871,14 @@  static int uclogic_params_huion_init(struct uclogic_params *params,
 	}
 
 	/* Try to get firmware version */
-	ver_ptr = kzalloc(ver_len, GFP_KERNEL);
-	if (ver_ptr == NULL) {
+	p.fw_name = kzalloc(ver_len, GFP_KERNEL);
+	if (!p.fw_name) {
 		rc = -ENOMEM;
 		goto cleanup;
 	}
-	rc = usb_string(udev, 201, ver_ptr, ver_len);
+	rc = usb_string(udev, 201, p.fw_name, ver_len);
 	if (rc == -EPIPE) {
-		*ver_ptr = '\0';
+		*p.fw_name = '\0';
 	} else if (rc < 0) {
 		hid_err(hdev,
 			"failed retrieving Huion firmware version: %d\n", rc);
@@ -885,7 +886,7 @@  static int uclogic_params_huion_init(struct uclogic_params *params,
 	}
 
 	/* If this is a transition firmware */
-	if (strcmp(ver_ptr, transition_ver) == 0) {
+	if (strcmp(p.fw_name, transition_ver) == 0) {
 		hid_dbg(hdev,
 			"transition firmware detected, not probing pen v2 parameters\n");
 	} else {
@@ -1028,7 +1029,6 @@  static int uclogic_params_huion_init(struct uclogic_params *params,
 	rc = 0;
 cleanup:
 	kfree(params_ptr);
-	kfree(ver_ptr);
 	uclogic_params_cleanup(&p);
 	return rc;
 }
diff --git a/drivers/hid/hid-uclogic-params.h b/drivers/hid/hid-uclogic-params.h
index d6ffadb2f601..412c916770f5 100644
--- a/drivers/hid/hid-uclogic-params.h
+++ b/drivers/hid/hid-uclogic-params.h
@@ -232,6 +232,11 @@  struct uclogic_params {
 	 * List of event hooks.
 	 */
 	struct uclogic_raw_event_hook *event_hooks;
+	/*
+	 * Firmware name, exposed to userspace via sysfs as it is used to
+	 * identify the tablet.
+	 */
+	char *fw_name;
 };
 
 /* Driver data */