Re: [PATCH v2 4/8] media: platform: amd: Add isp4 fw and hw interface

[Du, Bin]

Thanks Sakari Ailus for the comments

On 8/11/2025 7:46 PM, Sakari Ailus wrote:
> Hi Bin,
>
> On Tue, Jul 29, 2025 at 05:12:03PM +0800, Du, Bin wrote:
> > Many thanks Askari Ailus for your careful review
> >
> > On 7/28/2025 3:23 PM, Sakari Ailus wrote:
> > > Hi Bin,
> > >
> > > On Wed, Jun 18, 2025 at 05:19:55PM +0800, Bin Du wrote:
> > > > ISP firmware controls ISP HW pipeline using dedicated embedded processor
> > > > called ccpu.
> > > > The communication between ISP FW and driver is using commands and
> > > > response messages sent through the ring buffer. Command buffers support
> > > > either global setting that is not specific to the steam and support stream
> > > > specific parameters. Response buffers contains ISP FW notification
> > > > information such as frame buffer done and command done. IRQ is used for
> > > > receiving response buffer from ISP firmware, which is handled in the main
> > > > isp4 media device. ISP ccpu is booted up through the firmware loading
> > > > helper function prior to stream start.
> > > > Memory used for command buffer and response buffer needs to be allocated
> > > > from amdgpu buffer manager because isp4 is a child device of amdgpu.
> > >
> > > Please rewrap this, some lines above are quite short.
> > Thanks, the line after the short line is supposed to be a new paragraph?
> > Should we put all the description in one paragraph?
>
> One or more paragraphs work fine, but a new paragraph is separated from the
> previous one by another newline.
>
> ...

Got it, thanks.

> > > > +	void *cpu_ptr;
> > > > +	u64 gpu_addr;
> > > > +	u32 ret;
> > > > +
> > > > +	dev = ispif->dev;
> > > > +
> > > > +	if (!mem_size)
> > > > +		return NULL;
> > > > +
> > > > +	mem_info = kzalloc(sizeof(*mem_info), GFP_KERNEL);
> > > > +	if (!mem_info)
> > > > +		return NULL;
> > > > +
> > > > +	adev = (struct amdgpu_device *)ispif->adev;
> > >
> > > Why the cast?
> > >
> > > adev isn't a great name here as it's usually used for struct acpi_devices.
> > In the next patch, will use new helper function for this and will no longer
> > use amdgpu_device
>
> Use correct types when you can; either way this doesn't seem to be changed
> by the further patches in the set.
>
> ...

Yes, totally agree.

> > > > +static int isp4if_gpu_mem_free(struct isp4_interface *ispif,
> > > > +			       struct isp4if_gpu_mem_info *mem_info)
> > > > +{
> > > > +	struct device *dev = ispif->dev;
> > > > +	struct amdgpu_bo *bo;
> > > > +
> > > > +	if (!mem_info) {
> > > > +		dev_err(dev, "invalid mem_info\n");
> > > > +		return -EINVAL;
> > > > +	}
> > > > +
> > > > +	bo = (struct amdgpu_bo *)mem_info->mem_handle;
> > >
> > > Why do you need to cast here?
> > In the next patch, will use new helper function for this and will no longer
> > use amdgpu_bo
>
> Not quite, on top of this patch number 6 adds more of the same.
>
> ...

Thanks, will double check all new patches to avoid similar problem.

> > > > +static struct isp4if_cmd_element *
> > > > +isp4if_append_cmd_2_cmdq(struct isp4_interface *ispif,
> > > > +			 struct isp4if_cmd_element *cmd_ele)
> > > > +{
> > > > +	struct isp4if_cmd_element *copy_command = NULL;
> > > > +
> > > > +	copy_command = kmalloc(sizeof(*copy_command), GFP_KERNEL);
> > > > +	if (!copy_command)
> > > > +		return NULL;
> > > > +
> > > > +	memcpy(copy_command, cmd_ele, sizeof(*copy_command));
> > >
> > > kmemdup()?
> > Kmemdup is to allocate memory and copy, can't be used here.
>
> Isn't that what you're doing above?
>
> >

Yes, you are absolutely right. Sorry, missed the kmalloc before the 
memcpy, will fix in the next patch.

> > > > +
> > > > +	guard(mutex)(&ispif->cmdq_mutex);
> > > > +
> > > > +	list_add_tail(&copy_command->list, &ispif->cmdq);
> > > > +
> > > > +	return copy_command;
> > > > +}

Regards,
Bin