Re: [igt-dev] [PATCH i-g-t 6/6] lib/igt_device_scan: Improve Intel discrete GPU selection

[Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>]

On 27/01/2023 16:17, Kamil Konieczny wrote:
> Hi Tvrtko,
> 
> On 2023-01-27 at 11:12:41 +0000, Tvrtko Ursulin wrote:
>> From: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
>>
>> Now that DRM subsystem can contain PCI cards with the vendor set to Intel
>> but they are not Intel GPUs, we need a better selection logic than looking
>> at the vendor. Use the driver name instead.
>>
>> Caveat that the driver key was on a blacklist so far, and although I can't
>> imagine it can be slow to probe, this is something to double check.
>>
>> Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
>> Cc: Kamil Konieczny <kamil.konieczny@linux.intel.com>
>> Cc: Zbigniew Kempczyński <zbigniew.kempczynski@intel.com>
> 
> Please send this as separate patch, not in this series.

Yeah I was lazy and wanting to save time so okay.

>> ---
>>   lib/igt_device_scan.c | 7 +++++--
>>   1 file changed, 5 insertions(+), 2 deletions(-)
>>
>> diff --git a/lib/igt_device_scan.c b/lib/igt_device_scan.c
>> index ed128d24dd10..8b767eed202d 100644
>> --- a/lib/igt_device_scan.c
>> +++ b/lib/igt_device_scan.c
>> @@ -237,6 +237,7 @@ struct igt_device {
>>   	char *vendor;
>>   	char *device;
>>   	char *pci_slot_name;
>> +	char *driver;
>>   	int gpu_index; /* For more than one GPU with same vendor and device. */
>>   
>>   	char *codename; /* For grouping by codename */
>> @@ -440,7 +441,6 @@ static bool is_on_blacklist(const char *what)
>>   				      "resource3", "resource4", "resource5",
>>   				      "resource0_wc", "resource1_wc", "resource2_wc",
>>   				      "resource3_wc", "resource4_wc", "resource5_wc",
>> -				      "driver",
>>   				      "uevent", NULL};
>>   	const char *key;
>>   	int i = 0;
>> @@ -662,6 +662,8 @@ static struct igt_device *igt_device_new_from_udev(struct udev_device *dev)
>>   		get_pci_vendor_device(idev, &vendor, &device);
>>   		idev->codename = __pci_codename(vendor, device);
>>   		idev->dev_type = __pci_devtype(vendor, device, idev->pci_slot_name);
>> +		idev->driver = strdup_nullsafe(get_attr(idev, "driver"));
>> +		igt_assert(idev->driver);
>>   	}
>>   
>>   	return idev;
>> @@ -776,7 +778,7 @@ static bool __find_first_i915_card(struct igt_device_card *card, bool discrete)
>>   
>>   	igt_list_for_each_entry(dev, &igt_devs.all, link) {
>>   
>> -		if (!is_pci_subsystem(dev) || !is_vendor_matched(dev, "intel"))
>> +		if (!is_pci_subsystem(dev) || strcmp(dev->driver, "i915"))
> 
> Put the comment here why it can be problematic to relay on driver name.

Function name being __find_first_*i915*_card is IMO enough so it feels 
any comment to the same effect would be redundant.

Hm if anything igt_device_find_integrated_card should be renamed..

Regards,

Tvrtko

> 
> Regards,
> Kamil
> 
>>   			continue;
>>   
>>   		cmp = strncmp(dev->pci_slot_name, INTEGRATED_I915_GPU_PCI_ID,
>> @@ -1023,6 +1025,7 @@ static void igt_device_free(struct igt_device *dev)
>>   	free(dev->drm_render);
>>   	free(dev->vendor);
>>   	free(dev->device);
>> +	free(dev->driver);
>>   	free(dev->pci_slot_name);
>>   	g_hash_table_destroy(dev->attrs_ht);
>>   	g_hash_table_destroy(dev->props_ht);
>> -- 
>> 2.34.1
>>