[PATCH i-g-t v1] drmtest: drop legacy path from filtered opens

[Kamil Konieczny]

Function __drm_open_driver_another() has two paths, first being
for filtered devices, second for non-filtered ones. Separate
them and do not fallback into legacy path when index for card
exceeds number of filtered devices. Use local opened fds table
only for legacy calls as this table can become stale after
driver reload. In filtered one do not use opened fds guards as
this is pointless, we already have info about card wanted by user
and we do not need to check if we ancounter already opened one.
Also allow opening the same device if user wants it, for example
with repeating same card number in --device or IGT_DEVICE:

sudo IGT_DEVICE=pci:vendor=Intel,card=0\;pci:vendor=Intel,card=0 \
	build/tests/gem_basic --r multigpu-create-close

Cc: Arkadiusz Hiler <arek at hiler.eu>
Cc: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Chris Wilson <chris.p.wilson at linux.intel.com>
Cc: Janusz Krzysztofik <janusz.krzysztofik at linux.intel.com>
Cc: Petri Latvala <adrinael at adrinael.net>
Cc: Zbigniew Kempczyński <zbigniew.kempczynski at intel.com>
Signed-off-by: Kamil Konieczny <kamil.konieczny at linux.intel.com>
---
 lib/drmtest.c | 22 +++++++++++++---------
 1 file changed, 13 insertions(+), 9 deletions(-)

diff --git a/lib/drmtest.c b/lib/drmtest.c
index 52b5a2020..307c44ef6 100644
--- a/lib/drmtest.c
+++ b/lib/drmtest.c
@@ -481,13 +481,12 @@ static bool __get_card_for_nth_filter(int idx, struct igt_device_card *card)
  *
  * This function opens device in the following order:
  *
- * 1. when --device arguments are present:
+ * 1. when --device arguments are present or IGT_DEVICE env var is used:
  *   * device scanning is executed,
  *   * idx-th filter (starting with 0, filters are semicolon separated) is used
- *   * if there is no idx-th filter, goto 2
+ *   * if there is no idx-th filter fail with -1
  *   * first device maching the filter is selected
- *   * if it's already opened (for indexes = 0..idx-1) we fail with -1
- *   * otherwise open the device and return the fd
+ *   * open the device and return the fd
  *
  * 2. compatibility mode - open the first DRM device we can find that is not
  *    already opened for indexes 0..idx-1, searching up to 16 device nodes
@@ -528,10 +527,17 @@ int __drm_open_driver_another(int idx, int chipset)
 {
 	int fd = -1;
 
-	if (chipset != DRIVER_VGEM && igt_device_filter_count() > idx) {
+	if (chipset != DRIVER_VGEM && igt_device_filter_count()) {
+		int count = igt_device_filter_count();
 		struct igt_device_card card;
 		bool found;
 
+		if (idx < 0 || idx >= count) {
+			igt_warn("Cannot open, index into filter out of bounds: %d, count=%d\n",
+				 idx, count);
+			return -1;
+		}
+
 		found = __get_card_for_nth_filter(idx, &card);
 
 		if (!found) {
@@ -542,19 +548,17 @@ int __drm_open_driver_another(int idx, int chipset)
 		if (!found || !strlen(card.card))
 			igt_warn("No card matches the filter! [%s]\n",
 				 igt_device_filter_get(idx));
-		else if (_is_already_opened(card.card, idx))
-			igt_warn("card maching filter %d is already opened\n", idx);
 		else
 			fd = __open_driver_exact(card.card, chipset);
 
 	} else {
 		/* no filter for device idx, let's open whatever is available */
 		fd = __open_driver("/dev/dri/card", 0, chipset, idx);
+		if (fd >= 0)
+			_set_opened_fd(idx, fd);
 	}
 
 	if (fd >= 0) {
-		_set_opened_fd(idx, fd);
-
 		/* Cache xe_device struct. */
 		if (is_xe_device(fd))
 			xe_device_get(fd);
-- 
2.42.0