[PATCH i-g-t v5] lib/drmtest: drop legacy check from filtered opens

[Janusz Krzysztofik]

On Monday, 19 February 2024 18:35:34 CET Kamil Konieczny wrote:
> 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.

The _is_already_opened(fd) check, introduced together with 
__drm_open_driver_another() by commit 4e0597fd0c6eae ("lib/drmtest: Introduce 
__drm_open_driver_another"), was added to both legacy and filter based 
processing paths.  Commit description didn't clarify its purpose.

I'm not sure if and why we should keep it in the legacy path while removing it 
from the filter based.

Thanks,
Janusz

> 
> 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)
> v5: drop check for negative idx (Janusz, Zbigniew)
> 
> 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 | 7 ++-----
>  1 file changed, 2 insertions(+), 5 deletions(-)
> 
> diff --git a/lib/drmtest.c b/lib/drmtest.c
> index 52b5a2020..aa1096e96 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
> @@ -542,8 +541,6 @@ 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);
>  
>