[igt-dev] [V2] lib/igt_kms: Add a helper function to check Bigjoiner support

[Navare, Manasi]

On Thu, Jun 09, 2022 at 03:13:28PM +0530, Karthik B S wrote:
> On 6/8/2022 12:51 PM, Bhanuprakash Modem wrote:
> > Create a helper function to check that the system supports the
> > given crtc/connector mode(s).
> > 
> > Example:
> > * Pipe-D won't support Bigjoiner, hence we can't use the connector
> >    modes greater than 5K on Pipe-D
> > * To use 8K mode on a pipe, then the consecutive pipe must be free.
> > 
> > The Kernel is expected to reject the invalid combo (which must be
> > validated as a scenario separately). So, this helper function checks
> > the validity of the combo to avoid failures.
> > 
> > To use this helper, each individual subtest needs to set the @pipe
> > to a specific @output by igt_output_set_pipe() and call this helper
> > to check the validity of the combo.
> > 
> > V2:
> > * Rebase
> > * Add support to handle fused pipes
> > 
> > Signed-off-by: Bhanuprakash Modem <bhanuprakash.modem at intel.com>
> > Reviewed-by: Manasi Navare <manasi.d.navare at intel.com>
> > ---
> >   lib/igt_kms.c | 80 +++++++++++++++++++++++++++++++++++++++++++++++++++
> >   lib/igt_kms.h |  3 ++
> >   2 files changed, 83 insertions(+)
> > 
> > diff --git a/lib/igt_kms.c b/lib/igt_kms.c
> > index 36dfcfcb..74425db3 100644
> > --- a/lib/igt_kms.c
> > +++ b/lib/igt_kms.c
> > @@ -5636,3 +5636,83 @@ bool igt_check_output_bpc_equal(int drmfd, enum pipe pipe,
> >   	return (current == bpc);
> >   }
> > +
> > +static enum pipe find_pipe_index(const enum pipe pipe_seq[], enum pipe value)
> > +{
> > +	enum pipe index = PIPE_A;
> > +
> > +	while (index < IGT_MAX_PIPES && pipe_seq[index] != value)
> > +		index++;
> > +
> > +	return (index == IGT_MAX_PIPES) ? PIPE_NONE : index;
> > +}
> 
> Hi Bhanu,
> 
> I think big joiner is only supported on consecutive pipes (A+B, B+C, C+D).
> So in case of fused pipes where we don't have one of the pipes, this logic
> wouldn't be helpful. We would need a logic to reject a particular
> pipe/output combination in case we don't have the required consecutive pipe
> active.
> 
> Thanks,
> Karthik.B.S

Yes I agree, in case of single or multi display cases, we need to reject
the bigjoiner if the consecutive pipe is not available.

Manasi

> > +
> > +/*
> > + * igt_check_bigjoiner_support:
> > + * @display: a pointer to an #igt_display_t structure
> > + *
> > + * Get all active pipes from connected outputs (i.e. pending_pipe != PIPE_NONE)
> > + * and check those pipes supports the selected mode(s).
> > + *
> > + * Example:
> > + *  * Pipe-D can't support mode > 5K
> > + *  * To use 8K mode on a pipe then consecutive pipe must be free.
> > + *
> > + * Returns: true if a valid crtc/connector mode combo found, else false
> > + */
> > +bool igt_check_bigjoiner_support(igt_display_t *display)
> > +{
> > +	uint8_t i, total_pipes = 0, pipes_in_use = 0;
> > +	enum pipe p, pipe_seq[IGT_MAX_PIPES];
> > +	struct {
> > +		enum pipe idx;
> > +		drmModeModeInfo *mode;
> > +	} pipes[IGT_MAX_PIPES];
> > +
> > +	/* Get total enabled pipes. */
> > +	for_each_pipe(display, p) {
> > +		pipe_seq[total_pipes] = p;
> > +		total_pipes++;
> > +	}
> > +
> > +	/*
> > +	 * Get list of pipes in use those were set by igt_output_set_pipe()
> > +	 * just before calling this function.
> > +	 */
> > +	for (i = 0 ; i < display->n_outputs; i++) {
> > +		igt_output_t *output = &display->outputs[i];
> > +
> > +		if (output->pending_pipe == PIPE_NONE)
> > +			continue;
> > +
> > +		pipes[pipes_in_use].idx = find_pipe_index(pipe_seq, output->pending_pipe);
> > +		pipes[pipes_in_use].mode = igt_output_get_mode(output);
> > +		pipes_in_use++;
> > +	}
> > +
> > +	if (!pipes_in_use)
> > +		igt_skip("We must set atleast one output to pipe.\n");
> > +
> > +	/*
> > +	 * if mode.hdisplay > 5120, then ignore
> > +	 *  - last crtc in single/multi-connector config
> > +	 *  - consecutive crtcs in multi-connector config
> > +	 *
> > +	 * in multi-connector config ignore if
> > +	 *  - previous crtc mode.hdisplay > 5120 and
> > +	 *  - current & previous crtcs are consecutive
> > +	 */
> > +	for (i = 0; i < pipes_in_use; i++) {
> > +		if (((pipes[i].mode->hdisplay > MAX_HDISPLAY_PER_PIPE) &&
> > +		     ((pipes[i].idx >= (total_pipes - 1)) ||
> > +		      ((i < (pipes_in_use - 1)) && (abs(pipes[i + 1].idx - pipes[i].idx) <= 1)))) ||
> > +		    ((i > 0) && (pipes[i - 1].mode->hdisplay > MAX_HDISPLAY_PER_PIPE) &&
> > +		     (abs(pipes[i].idx - pipes[i - 1].idx) <= 1))) {
> > +			igt_debug("Pipe/Output combo is not possible with selected mode(s).\n");
> > +
> > +			return false;
> > +		}
> > +	}
> > +
> > +	return true;
> > +}
> > diff --git a/lib/igt_kms.h b/lib/igt_kms.h
> > index 0f12d825..3e674e74 100644
> > --- a/lib/igt_kms.h
> > +++ b/lib/igt_kms.h
> > @@ -109,6 +109,7 @@ const char *kmstest_connector_status_str(int status);
> >   const char *kmstest_connector_type_str(int type);
> >   void kmstest_dump_mode(drmModeModeInfo *mode);
> > +#define MAX_HDISPLAY_PER_PIPE 5120
> >   int kmstest_get_pipe_from_crtc_id(int fd, int crtc_id);
> >   void kmstest_set_vt_graphics_mode(void);
> > @@ -967,4 +968,6 @@ int sort_drm_modes_by_res_asc(const void *a, const void *b);
> >   void igt_sort_connector_modes(drmModeConnector *connector,
> >   		int (*comparator)(const void *, const void*));
> > +bool igt_check_bigjoiner_support(igt_display_t *display);
> > +
> >   #endif /* __IGT_KMS_H__ */
> 
>