Re: [PATCH] drm/amd/amdgpu: Fix assingment in if condition in amdgpu_irq.c

["Christian König" <christian.koenig@amd.com>]

Am 05.05.23 um 16:59 schrieb Srinivasan Shanmugam:
> Assignments in if condition are less readable and error-prone.
>
> Fixes below error & warnings reported by checkpatch"
>
> ERROR: do not use assignment in if condition
> +       } else if ((src = adev->irq.client[client_id].sources[src_id])) {
>
> WARNING: braces {} are not necessary for any arm of this statement
> WARNING: Prefer 'unsigned int' to bare use of 'unsigned'
>
> Cc: Christian König <christian.koenig@amd.com>
> Cc: Alex Deucher <alexander.deucher@amd.com>
> Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmugam@amd.com>
> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c | 27 +++++++++++++------------
>   1 file changed, 14 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c
> index c8413470e057..f312e8ca0015 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c
> @@ -110,7 +110,7 @@ const char *soc15_ih_clientid_name[] = {
>   void amdgpu_irq_disable_all(struct amdgpu_device *adev)
>   {
>   	unsigned long irqflags;
> -	unsigned i, j, k;
> +	unsigned int i, j, k;
>   	int r;
>   
>   	spin_lock_irqsave(&adev->irq.lock, irqflags);
> @@ -269,11 +269,11 @@ int amdgpu_irq_init(struct amdgpu_device *adev)
>   		int nvec = pci_msix_vec_count(adev->pdev);
>   		unsigned int flags;
>   
> -		if (nvec <= 0) {
> +		if (nvec <= 0)
>   			flags = PCI_IRQ_MSI;
> -		} else {
> +		else
>   			flags = PCI_IRQ_MSI | PCI_IRQ_MSIX;
> -		}
> +
>   		/* we only need one vector */
>   		nvec = pci_alloc_irq_vectors(adev->pdev, 1, 1, flags);
>   		if (nvec > 0) {
> @@ -332,7 +332,7 @@ void amdgpu_irq_fini_hw(struct amdgpu_device *adev)
>    */
>   void amdgpu_irq_fini_sw(struct amdgpu_device *adev)
>   {
> -	unsigned i, j;
> +	unsigned int i, j;
>   
>   	for (i = 0; i < AMDGPU_IRQ_CLIENTID_MAX; ++i) {
>   		if (!adev->irq.client[i].sources)
> @@ -366,7 +366,7 @@ void amdgpu_irq_fini_sw(struct amdgpu_device *adev)
>    * 0 on success or error code otherwise
>    */
>   int amdgpu_irq_add_id(struct amdgpu_device *adev,
> -		      unsigned client_id, unsigned src_id,
> +		      unsigned int client_id, unsigned int src_id,
>   		      struct amdgpu_irq_src *source)
>   {
>   	if (client_id >= AMDGPU_IRQ_CLIENTID_MAX)
> @@ -418,7 +418,7 @@ void amdgpu_irq_dispatch(struct amdgpu_device *adev,
>   {
>   	u32 ring_index = ih->rptr >> 2;
>   	struct amdgpu_iv_entry entry;
> -	unsigned client_id, src_id;
> +	unsigned int client_id, src_id;
>   	struct amdgpu_irq_src *src;
>   	bool handled = false;
>   	int r;
> @@ -431,6 +431,7 @@ void amdgpu_irq_dispatch(struct amdgpu_device *adev,
>   
>   	client_id = entry.client_id;
>   	src_id = entry.src_id;
> +	src = adev->irq.client[client_id].sources[src_id];

That won't work like this. We first need to validate the client_id and 
src_id values or otherwise this can crash.

That's why we have the assignment inside the if in the first place.

Christian.

>   
>   	if (client_id >= AMDGPU_IRQ_CLIENTID_MAX) {
>   		DRM_DEBUG("Invalid client_id in IV: %d\n", client_id);
> @@ -446,7 +447,7 @@ void amdgpu_irq_dispatch(struct amdgpu_device *adev,
>   		DRM_DEBUG("Unregistered interrupt client_id: %d src_id: %d\n",
>   			  client_id, src_id);
>   
> -	} else if ((src = adev->irq.client[client_id].sources[src_id])) {
> +	} else if (src) {
>   		r = src->funcs->process(adev, src, &entry);
>   		if (r < 0)
>   			DRM_ERROR("error processing interrupt (%d)\n", r);
> @@ -493,7 +494,7 @@ void amdgpu_irq_delegate(struct amdgpu_device *adev,
>    * Updates interrupt state for the specific source (all ASICs).
>    */
>   int amdgpu_irq_update(struct amdgpu_device *adev,
> -			     struct amdgpu_irq_src *src, unsigned type)
> +			     struct amdgpu_irq_src *src, unsigned int type)
>   {
>   	unsigned long irqflags;
>   	enum amdgpu_interrupt_state state;
> @@ -556,7 +557,7 @@ void amdgpu_irq_gpu_reset_resume_helper(struct amdgpu_device *adev)
>    * 0 on success or error code otherwise
>    */
>   int amdgpu_irq_get(struct amdgpu_device *adev, struct amdgpu_irq_src *src,
> -		   unsigned type)
> +		   unsigned int type)
>   {
>   	if (!adev->irq.installed)
>   		return -ENOENT;
> @@ -586,7 +587,7 @@ int amdgpu_irq_get(struct amdgpu_device *adev, struct amdgpu_irq_src *src,
>    * 0 on success or error code otherwise
>    */
>   int amdgpu_irq_put(struct amdgpu_device *adev, struct amdgpu_irq_src *src,
> -		   unsigned type)
> +		   unsigned int type)
>   {
>   	if (!adev->irq.installed)
>   		return -ENOENT;
> @@ -620,7 +621,7 @@ int amdgpu_irq_put(struct amdgpu_device *adev, struct amdgpu_irq_src *src,
>    * invalid parameters
>    */
>   bool amdgpu_irq_enabled(struct amdgpu_device *adev, struct amdgpu_irq_src *src,
> -			unsigned type)
> +			unsigned int type)
>   {
>   	if (!adev->irq.installed)
>   		return false;
> @@ -733,7 +734,7 @@ void amdgpu_irq_remove_domain(struct amdgpu_device *adev)
>    * Returns:
>    * Linux IRQ
>    */
> -unsigned amdgpu_irq_create_mapping(struct amdgpu_device *adev, unsigned src_id)
> +unsigned int amdgpu_irq_create_mapping(struct amdgpu_device *adev, unsigned int src_id)
>   {
>   	adev->irq.virq[src_id] = irq_create_mapping(adev->irq.domain, src_id);
>