[PATCH v3 0/3] HID: nvidia-shield: Fix the error handling path of shield_probe()

[PATCH v3 0/3] HID: nvidia-shield: Fix the error handling path of shield_probe()

[Rahul Rameshbabu]

This series fixes some missing clean-up function calls in the error handling of
the probe.

Patch 1 and 2 fix some similar issues introduced in 2 different commits (hence 2
patches)

Patch 3 is an enhancement that creates a common function for cleaning up
thunderstrike instances.

Changes:

  v1->v2:
    - Add the LED_RETAIN_AT_SHUTDOWN flag to prevent
      led_classdev_unregister from trying to set the LED to off before a
      successful call to hid_hw_start.
    - Rename err_haptics label to err_ts_create to make the label name more
      accurate.
    - Re-order operations in thunderstrike_destroy to be in LIFO order with
      regards to the operations in thunderstrike_create.
  v2->v3:
    - Refactor thunderstrike_destroy to take a thunderstrike instance
      pointer as a parameter and prevent a variable from being unused
      in shield_probe.

Link: https://lore.kernel.org/linux-input/cover.1693070958.git.christophe.jaillet@wanadoo.fr/
Link: https://lore.kernel.org/linux-input/20230918041345.59859-1-rrameshbabu@nvidia.com/

Notes from Rahul:
  - Thank you so much Christophe for these patches.
  - Sent v2 without accounting for the fact that thunderstrike_destroy in v1
    makes the thunderstrike instance in shield_probe unused. Tested v3 with W=1.

Christophe JAILLET (3):
  HID: nvidia-shield: Fix a missing led_classdev_unregister() in the
    probe error handling path
  HID: nvidia-shield: Fix some missing function calls() in the probe
    error handling path
  HID: nvidia-shield: Introduce thunderstrike_destroy()

 drivers/hid/hid-nvidia-shield.c | 24 ++++++++++++++----------
 1 file changed, 14 insertions(+), 10 deletions(-)

-- 
2.40.1

[PATCH v3 1/3] HID: nvidia-shield: Fix a missing led_classdev_unregister() in the probe error handling path

[Rahul Rameshbabu]

From: Christophe JAILLET <christophe.jaillet@wanadoo.fr>

The commit in Fixes updated the error handling path of
thunderstrike_create() and the remove function but not the error handling
path of shield_probe(), should an error occur after a successful
thunderstrike_create() call.

Add the missing call. Make sure it is safe to call in the probe error
handling path by preventing the led_classdev from attempting to set the LED
brightness to the off state on unregister.

Fixes: f88af60e74a5 ("HID: nvidia-shield: Support LED functionality for Thunderstrike")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: Rahul Rameshbabu <rrameshbabu@nvidia.com>
---

Notes:
    Changes:
    
      v1->v2:
        - Add the LED_RETAIN_AT_SHUTDOWN flag to prevent
          led_classdev_unregister from trying to set the LED to off before a
          successful call to hid_hw_start.
      v2->v3:
        - No changes.

 drivers/hid/hid-nvidia-shield.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/hid/hid-nvidia-shield.c b/drivers/hid/hid-nvidia-shield.c
index 43784bb57d3f..c144641452d3 100644
--- a/drivers/hid/hid-nvidia-shield.c
+++ b/drivers/hid/hid-nvidia-shield.c
@@ -801,7 +801,7 @@ static inline int thunderstrike_led_create(struct thunderstrike *ts)
 	led->name = devm_kasprintf(&ts->base.hdev->dev, GFP_KERNEL,
 				   "thunderstrike%d:blue:led", ts->id);
 	led->max_brightness = 1;
-	led->flags = LED_CORE_SUSPENDRESUME;
+	led->flags = LED_CORE_SUSPENDRESUME | LED_RETAIN_AT_SHUTDOWN;
 	led->brightness_get = &thunderstrike_led_get_brightness;
 	led->brightness_set = &thunderstrike_led_set_brightness;
 
@@ -1076,6 +1076,7 @@ static int shield_probe(struct hid_device *hdev, const struct hid_device_id *id)
 err_haptics:
 	if (ts->haptics_dev)
 		input_unregister_device(ts->haptics_dev);
+	led_classdev_unregister(&ts->led_dev);
 	return ret;
 }
 
-- 
2.40.1

[PATCH v3 2/3] HID: nvidia-shield: Fix some missing function calls() in the probe error handling path

[Rahul Rameshbabu]

From: Christophe JAILLET <christophe.jaillet@wanadoo.fr>

The commit in Fixes updated the error handling path of
thunderstrike_create() and the remove function but not the error handling
path of shield_probe(), should an error occur after a successful
thunderstrike_create() call.

Add the missing calls.

Fixes: 3ab196f88237 ("HID: nvidia-shield: Add battery support for Thunderstrike")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: Rahul Rameshbabu <rrameshbabu@nvidia.com>
---

Notes:
    Changes:
    
      v1->v2:
        - Rename err_haptics label to err_ts_create to make the label name more
          accurate.
      v2->v3:
        - No changes.

 drivers/hid/hid-nvidia-shield.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/hid/hid-nvidia-shield.c b/drivers/hid/hid-nvidia-shield.c
index c144641452d3..a566f9cdc97d 100644
--- a/drivers/hid/hid-nvidia-shield.c
+++ b/drivers/hid/hid-nvidia-shield.c
@@ -1058,7 +1058,7 @@ static int shield_probe(struct hid_device *hdev, const struct hid_device_id *id)
 	ret = hid_hw_start(hdev, HID_CONNECT_HIDINPUT);
 	if (ret) {
 		hid_err(hdev, "Failed to start HID device\n");
-		goto err_haptics;
+		goto err_ts_create;
 	}
 
 	ret = hid_hw_open(hdev);
@@ -1073,10 +1073,12 @@ static int shield_probe(struct hid_device *hdev, const struct hid_device_id *id)
 
 err_stop:
 	hid_hw_stop(hdev);
-err_haptics:
+err_ts_create:
+	power_supply_unregister(ts->base.battery_dev.psy);
 	if (ts->haptics_dev)
 		input_unregister_device(ts->haptics_dev);
 	led_classdev_unregister(&ts->led_dev);
+	ida_free(&thunderstrike_ida, ts->id);
 	return ret;
 }
 
-- 
2.40.1

[PATCH v3 3/3] HID: nvidia-shield: Introduce thunderstrike_destroy()

[Rahul Rameshbabu]

From: Christophe JAILLET <christophe.jaillet@wanadoo.fr>

In order to simplify some error handling paths and avoid code duplication,
introduce thunderstrike_destroy() which undoes thunderstrike_create().

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: Rahul Rameshbabu <rrameshbabu@nvidia.com>
---

Notes:
    Changes:
    
      v1->v2:
        - Re-order operations in thunderstrike_destroy to be in LIFO order with
          regards to the operations in thunderstrike_create.
      v2->v3:
        - Refactor thunderstrike_destroy to take a thunderstrike instance
          pointer as a parameter and prevent a variable from being unused
          in shield_probe.

 drivers/hid/hid-nvidia-shield.c | 21 +++++++++++----------
 1 file changed, 11 insertions(+), 10 deletions(-)

diff --git a/drivers/hid/hid-nvidia-shield.c b/drivers/hid/hid-nvidia-shield.c
index a566f9cdc97d..bc47e19ef117 100644
--- a/drivers/hid/hid-nvidia-shield.c
+++ b/drivers/hid/hid-nvidia-shield.c
@@ -915,6 +915,15 @@ static struct shield_device *thunderstrike_create(struct hid_device *hdev)
 	return ERR_PTR(ret);
 }
 
+static void thunderstrike_destroy(struct thunderstrike *ts)
+{
+	led_classdev_unregister(&ts->led_dev);
+	power_supply_unregister(ts->base.battery_dev.psy);
+	if (ts->haptics_dev)
+		input_unregister_device(ts->haptics_dev);
+	ida_free(&thunderstrike_ida, ts->id);
+}
+
 static int android_input_mapping(struct hid_device *hdev, struct hid_input *hi,
 				 struct hid_field *field,
 				 struct hid_usage *usage, unsigned long **bit,
@@ -1074,11 +1083,7 @@ static int shield_probe(struct hid_device *hdev, const struct hid_device_id *id)
 err_stop:
 	hid_hw_stop(hdev);
 err_ts_create:
-	power_supply_unregister(ts->base.battery_dev.psy);
-	if (ts->haptics_dev)
-		input_unregister_device(ts->haptics_dev);
-	led_classdev_unregister(&ts->led_dev);
-	ida_free(&thunderstrike_ida, ts->id);
+	thunderstrike_destroy(ts);
 	return ret;
 }
 
@@ -1090,11 +1095,7 @@ static void shield_remove(struct hid_device *hdev)
 	ts = container_of(dev, struct thunderstrike, base);
 
 	hid_hw_close(hdev);
-	power_supply_unregister(dev->battery_dev.psy);
-	if (ts->haptics_dev)
-		input_unregister_device(ts->haptics_dev);
-	led_classdev_unregister(&ts->led_dev);
-	ida_free(&thunderstrike_ida, ts->id);
+	thunderstrike_destroy(ts);
 	del_timer_sync(&ts->psy_stats_timer);
 	cancel_work_sync(&ts->hostcmd_req_work);
 	hid_hw_stop(hdev);
-- 
2.40.1

Re: [PATCH v3 0/3] HID: nvidia-shield: Fix the error handling path of shield_probe()

[Jiri Kosina]

On Mon, 18 Sep 2023, Rahul Rameshbabu wrote:

> This series fixes some missing clean-up function calls in the error handling of
> the probe.
> 
> Patch 1 and 2 fix some similar issues introduced in 2 different commits (hence 2
> patches)
> 
> Patch 3 is an enhancement that creates a common function for cleaning up
> thunderstrike instances.
> 
> Changes:
> 
>   v1->v2:
>     - Add the LED_RETAIN_AT_SHUTDOWN flag to prevent
>       led_classdev_unregister from trying to set the LED to off before a
>       successful call to hid_hw_start.
>     - Rename err_haptics label to err_ts_create to make the label name more
>       accurate.
>     - Re-order operations in thunderstrike_destroy to be in LIFO order with
>       regards to the operations in thunderstrike_create.
>   v2->v3:
>     - Refactor thunderstrike_destroy to take a thunderstrike instance
>       pointer as a parameter and prevent a variable from being unused
>       in shield_probe.
> 
> Link: https://lore.kernel.org/linux-input/cover.1693070958.git.christophe.jaillet@wanadoo.fr/
> Link: https://lore.kernel.org/linux-input/20230918041345.59859-1-rrameshbabu@nvidia.com/
> 
> Notes from Rahul:
>   - Thank you so much Christophe for these patches.
>   - Sent v2 without accounting for the fact that thunderstrike_destroy in v1
>     makes the thunderstrike instance in shield_probe unused. Tested v3 with W=1.
> 
> Christophe JAILLET (3):
>   HID: nvidia-shield: Fix a missing led_classdev_unregister() in the
>     probe error handling path
>   HID: nvidia-shield: Fix some missing function calls() in the probe
>     error handling path
>   HID: nvidia-shield: Introduce thunderstrike_destroy()

I have applied 1/3 and 2/3 to for-6.6/upstream-fixes and 3/3 to 
for-6.7/nvidia-shield.

Thanks,

-- 
Jiri Kosina
SUSE Labs