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

[Tvrtko Ursulin]

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.ursu...@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.ursu...@intel.com>
Cc: Kamil Konieczny <kamil.koniec...@linux.intel.com>
Cc: Zbigniew Kempczyński <zbigniew.kempczyn...@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