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

[Modem, Bhanuprakash]

On Fri-13-05-2022 01:35 am, Navare, Manasi wrote:
> On Mon, May 02, 2022 at 08:21:14PM +0530, 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 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.
> 
> Thank you for taking a stab at cleaning this up and adding this check in
> IGT.
> 
> In all cases, always the bigjoiner can only be supported on pipes 0 -
> total_pipes - 1
> So say the total pipes available in the platform are n, any mode > 5K
> can only be requested on pipes 0- n-1 and will be rejected on pipe n.
> 
> Cant we just use this simple check in igt_check_bigjoiner_support() {
> 
> total_pipes = n; (based on platform hardcode that say now for all
> platforms that support bigjoiner, total_pipes = 4)
> If mode > 5K and pipe = 4,
> skip test
> }

Totally agreed in case of single display config. What about multidisplay 
config?

There are many scenarios that we need to consider.
Example:
1) Assume we have a setup with two 8K monitors connected and 4 pipes 
enabled, then the only possible combinations are:

Pipe-A-Output-1, Pipe-C-Output-2
Pipe-C-Output-1, Pipe-A-Output-1

2) Assume we have 2 monitors connected (one 8K, one 4K) and 4 pipes 
enabled, then the possible combinations are:

Pipe-A-4K, Pipe-B-8K
Pipe-A-4K, Pipe-C-8K
Pipe-A-8K, Pipe-C-4K
Pipe-A-8K, Pipe-D-4K
Pipe-B-4K, Pipe-C-8K
Pipe-B-8K, Pipe-D-4K

- Bhanu

> 
> Manasi
> 
>>
>> Signed-off-by: Bhanuprakash Modem <bhanuprakash.modem at intel.com>
>> ---
>>   lib/igt_kms.c | 66 +++++++++++++++++++++++++++++++++++++++++++++++++++
>>   lib/igt_kms.h |  2 ++
>>   2 files changed, 68 insertions(+)
>>
>> diff --git a/lib/igt_kms.c b/lib/igt_kms.c
>> index 7838ff28..e277193d 100644
>> --- a/lib/igt_kms.c
>> +++ b/lib/igt_kms.c
>> @@ -5379,3 +5379,69 @@ int igt_get_dsc_debugfs_fd(int drmfd, drmModeConnector *connector)
>>   
>>   	return openat(igt_debugfs_dir(drmfd), file_name, O_WRONLY);
>>   }
>> +
>> +/*
>> + * 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
>> + *
>> + * 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, active_pipes = 0;
>> +	enum pipe p;
>> +	struct {
>> +		enum pipe idx;
>> +		drmModeModeInfo *mode;
>> +	} pipes[IGT_MAX_PIPES];
>> +
>> +	/* Get total enabled pipes. */
>> +	for_each_pipe(display, p)
>> +		total_pipes++;
>> +
>> +	/*
>> +	 * Get list of active pipes 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[active_pipes].idx = output->pending_pipe;
>> +		pipes[active_pipes].mode = igt_output_get_mode(output);
>> +		active_pipes++;
>> +	}
>> +
>> +	if (active_pipes)
>> +		return true;
>> +
>> +	/*
>> +	 * 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 < active_pipes; i++) {
>> +		if (((pipes[i].mode->hdisplay > MAX_HDISPLAY_PER_PIPE) &&
>> +		     ((pipes[i].idx >= (total_pipes - 1)) ||
>> +		      ((i < (active_pipes - 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("CRTC/Connector 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 e9ecd21e..8a14bb3c 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);
>> @@ -947,5 +948,6 @@ int igt_force_dsc_enable(int drmfd, drmModeConnector *connector);
>>   int igt_force_dsc_enable_bpp(int drmfd, drmModeConnector *connector,
>>   				int bpp);
>>   int igt_get_dsc_debugfs_fd(int drmfd, drmModeConnector *connector);
>> +bool igt_check_bigjoiner_support(igt_display_t *display);
>>   
>>   #endif /* __IGT_KMS_H__ */
>> -- 
>> 2.35.1
>>