[PATCH i-g-t v4] lib/drmtest: drop legacy check from filtered opens

[Kamil Konieczny]

For some multi-GPU tests user can check them on single-GPU board
with the help of repeating same card in --device option or
environment var IGT_DEVICE:

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

but is unable to use it due to current implementation of device
opening in function __drm_open_driver_another().

To allow this drop legacy check for already opened device when
using filters.

v2: improving description, using filtered_count var (Janusz)
  changing drmtest: to lib/drmtest: (Kamil)
  adding Lukasz Laguna to Cc: (Kamil)
v3: for out-of-bound index print debug, not a warning (Kamil)
v4: restored using filters number for filtered path and restored
  setting opened fds for legacy tests, changed description (Kamil)

Cc: Arkadiusz Hiler <arek at hiler.eu>
Cc: Chris Wilson <chris.p.wilson at linux.intel.com>
Cc: Janusz Krzysztofik <janusz.krzysztofik at linux.intel.com>
Cc: Lukasz Laguna <lukasz.laguna at 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>
Reviewed-by: "Zbigniew Kempczyński" <zbigniew.kempczynski at intel.com>
---
 lib/drmtest.c | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/lib/drmtest.c b/lib/drmtest.c
index 52b5a2020..43e6c0158 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
  *   * 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
@@ -526,12 +525,19 @@ static bool __get_card_for_nth_filter(int idx, struct igt_device_card *card)
  */
 int __drm_open_driver_another(int idx, int chipset)
 {
+	int filter_count = igt_device_filter_count();
 	int fd = -1;
 
-	if (chipset != DRIVER_VGEM && igt_device_filter_count() > idx) {
+	if (chipset != DRIVER_VGEM && idx < filter_count) {
 		struct igt_device_card card;
 		bool found;
 
+		if (idx < 0) {
+			igt_debug("Cannot open, index out of bounds: %d, filter_count=%d\n",
+				 idx, filter_count);
+			return -1;
+		}
+
 		found = __get_card_for_nth_filter(idx, &card);
 
 		if (!found) {
@@ -542,8 +548,6 @@ 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);
 
-- 
2.42.0