[Intel-gfx] [PATCH v3 4/9] PCI/VGA: Improve the default VGA device selection

[suijingfeng]

Hi,


Thanks for you noticed my change.


On 2023/7/20 03:32, Bjorn Helgaas wrote:
>> @@ -1509,13 +1543,24 @@ static int pci_notify(struct notifier_block *nb, unsigned long action,
>>   	 * cases of hotplugable vga cards.
>>   	 */
>>   
>> -	if (action == BUS_NOTIFY_ADD_DEVICE)
>> +	switch (action) {
>> +	case BUS_NOTIFY_ADD_DEVICE:
>>   		notify = vga_arbiter_add_pci_device(pdev);
>> -	else if (action == BUS_NOTIFY_DEL_DEVICE)
>> +		if (notify)
>> +			vga_arbiter_notify_clients();
>> +		break;
>> +	case BUS_NOTIFY_DEL_DEVICE:
>>   		notify = vga_arbiter_del_pci_device(pdev);
>> +		if (notify)
>> +			vga_arbiter_notify_clients();
>> +		break;
>> +	case BUS_NOTIFY_BOUND_DRIVER:
>> +		vga_arbiter_do_arbitration(pdev);
>> +		break;
>> +	default:
>> +		break;
>> +	}
> Changing from if/else to switch makes the patch bigger than necessary
> for no real benefit and obscures what is really changing.

Actually, the logic become more clear after this patch applied.

```

     switch (action) {
     case BUS_NOTIFY_ADD_DEVICE:
         notify = vga_arbiter_add_pci_device(pdev);
         if (notify)
             vga_arbiter_notify_clients();
         break;
     case BUS_NOTIFY_DEL_DEVICE:
         notify = vga_arbiter_del_pci_device(pdev);
         if (notify)
             vga_arbiter_notify_clients();
         break;
     case BUS_NOTIFY_BOUND_DRIVER:
         vga_arbiter_do_arbitration(pdev);
         break;
     default:
         break;
     }

```


Because we only need call vga_arbiter_notify_clients() when action == 
BUS_NOTIFY_ADD_DEVICE or action == BUS_NOTIFY_DEL_DEVICE,

But *NOT* when the action equals to  BUS_NOTIFY_BOUND_DRIVER.