[PATCH] drm/vc4: remove all usages of of_node_put()

[Amer Al Shanawany]

On 18/06/2024 13.54, Amer Al Shanawany wrote:
> On 5/22/24 16:48, Amer Al Shanawany wrote:
>> On 27/04/2024 15.40, Amer Al Shanawany wrote:
>>> Use the scope-based cleanup feature to clean up 'struct device_node *'
>>> when they go out of scope, and remove all instances of of_node_put()
>>> within the same scope, to simplify function exit and avoid potential
>>> memory leaks.
>>>
>>> Suggested-by: Julia Lawall <julia.lawall at inria.fr>
>>> Signed-off-by: Amer Al Shanawany <amer.shanawany at gmail.com>
>>> ---
>>>    drivers/gpu/drm/vc4/vc4_drv.c  | 14 ++++++--------
>>>    drivers/gpu/drm/vc4/vc4_hdmi.c |  4 +---
>>>    drivers/gpu/drm/vc4/vc4_hvs.c  |  4 +---
>>>    3 files changed, 8 insertions(+), 14 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/vc4/vc4_drv.c b/drivers/gpu/drm/vc4/vc4_drv.c
>>> index c133e96b8aca..bb0bb052e595 100644
>>> --- a/drivers/gpu/drm/vc4/vc4_drv.c
>>> +++ b/drivers/gpu/drm/vc4/vc4_drv.c
>>> @@ -289,7 +289,6 @@ static int vc4_drm_bind(struct device *dev)
>>>        struct rpi_firmware *firmware = NULL;
>>>        struct drm_device *drm;
>>>        struct vc4_dev *vc4;
>>> -    struct device_node *node;
>>>        struct drm_crtc *crtc;
>>>        bool is_vc5;
>>>        int ret = 0;
>>> @@ -302,11 +301,10 @@ static int vc4_drm_bind(struct device *dev)
>>>        else
>>>            driver = &vc4_drm_driver;
>>>    -    node = of_find_matching_node_and_match(NULL, vc4_dma_range_matches,
>>> -                           NULL);
>>> +    struct device_node *node __free(device_node) =
>>> +        of_find_matching_node_and_match(NULL, vc4_dma_range_matches, NULL);
>>>        if (node) {
>>>            ret = of_dma_configure(dev, node, true);
>>> -        of_node_put(node);
>>>              if (ret)
>>>                return ret;
>>> @@ -341,10 +339,10 @@ static int vc4_drm_bind(struct device *dev)
>>>                goto err;
>>>        }
>>>    -    node = of_find_compatible_node(NULL, NULL, "raspberrypi,bcm2835-firmware");
>>> -    if (node) {
>>> -        firmware = rpi_firmware_get(node);
>>> -        of_node_put(node);
>>> +    struct device_node *np __free(device_node) =
>>> +        of_find_compatible_node(NULL, NULL, "raspberrypi,bcm2835-firmware");
>>> +    if (np) {
>>> +        firmware = rpi_firmware_get(np);
>>>              if (!firmware) {
>>>                ret = -EPROBE_DEFER;
>>> diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c
>>> index d30f8e8e8967..915e8da3f41a 100644
>>> --- a/drivers/gpu/drm/vc4/vc4_hdmi.c
>>> +++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
>>> @@ -3661,7 +3661,6 @@ static int vc4_hdmi_bind(struct device *dev, struct device *master, void *data)
>>>        struct drm_device *drm = dev_get_drvdata(master);
>>>        struct vc4_hdmi *vc4_hdmi;
>>>        struct drm_encoder *encoder;
>>> -    struct device_node *ddc_node;
>>>        int ret;
>>>          vc4_hdmi = drmm_kzalloc(drm, sizeof(*vc4_hdmi), GFP_KERNEL);
>>> @@ -3699,14 +3698,13 @@ static int vc4_hdmi_bind(struct device *dev, struct device *master, void *data)
>>>        if (ret)
>>>            return ret;
>>>    -    ddc_node = of_parse_phandle(dev->of_node, "ddc", 0);
>>> +    struct device_node *ddc_node __free(device_node) = of_parse_phandle(dev->of_node, "ddc", 0);
>>>        if (!ddc_node) {
>>>            DRM_ERROR("Failed to find ddc node in device tree\n");
>>>            return -ENODEV;
>>>        }
>>>          vc4_hdmi->ddc = of_find_i2c_adapter_by_node(ddc_node);
>>> -    of_node_put(ddc_node);
>>>        if (!vc4_hdmi->ddc) {
>>>            DRM_DEBUG("Failed to get ddc i2c adapter by node\n");
>>>            return -EPROBE_DEFER;
>>> diff --git a/drivers/gpu/drm/vc4/vc4_hvs.c b/drivers/gpu/drm/vc4/vc4_hvs.c
>>> index 04af672caacb..6e3613e06e09 100644
>>> --- a/drivers/gpu/drm/vc4/vc4_hvs.c
>>> +++ b/drivers/gpu/drm/vc4/vc4_hvs.c
>>> @@ -845,15 +845,13 @@ static int vc4_hvs_bind(struct device *dev, struct device *master, void *data)
>>>          if (vc4->is_vc5) {
>>>            struct rpi_firmware *firmware;
>>> -        struct device_node *node;
>>> +        struct device_node *node __free(device_node) = rpi_firmware_find_node();
>>>            unsigned int max_rate;
>>>    -        node = rpi_firmware_find_node();
>>>            if (!node)
>>>                return -EINVAL;
>>>              firmware = rpi_firmware_get(node);
>>> -        of_node_put(node);
>>>            if (!firmware)
>>>                return -EPROBE_DEFER;
>>>    
>> Hi,
>>
>> This patch is marked as new/archived on patchwork[1], however it didn't receive any feedback, and a similar patch has been already merged [2].
>>
>>
>> [1]: https://patchwork.kernel.org/project/dri-devel/patch/20240427134044.38910-1-amer.shanawany@gmail.com/
>>
>> [2]: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=d65bfb9546eb627e3c578336355c5b81797f2255
>>
>> Thank you
>>
>> Amer
>>
> Hello,
> 
> Could anyone kindly provide some feedback on this patch?
> 
> Thank you
> 
> Amer
Hello all,

I have come to realize that unsubscribing from the mailing list shortly 
after sending this patch prevented me from receiving any feedback. My 
apologies for this oversight.

Thank you

Amer