[PATCH v2 5/5] media: iris: Fix frame interval enumeration for non-divisor framerates

iris_enum_frameintervals() advertised frame intervals using
V4L2_FRMIVAL_TYPE_STEPWISE with step=1/MAXIMUM_FPS where MAXIMUM_FPS
is 480. This caused client to enumerate only framerates of the form
MAXIMUM_FPS/n (where n is a positive integer), restricting support to
exact divisors of MAXIMUM_FPS (e.g., 480, 240, 160, 120, 96, 80, 60,
30, 24, 1).

Framerates that are not exact divisors of MAXIMUM_FPS, such as 29 fps,
25 fps, were excluded from the enumerated list. There is no hardware
restriction to framerates that are exact divisors of MAXIMUM_FPS. This
caused GStreamer caps negotiation to fail with an "internal data
stream error" when encoding content at such framerates.

Fix this by using V4L2_FRMIVAL_TYPE_CONTINUOUS. With CONTINUOUS type,
GStreamer creates a continuous framerate range [1, max_fps], allowing
any integer framerate within the range to pass caps negotiation. The
step field is set to 1/1 as required by the V4L2 specification for
continuous frame intervals.

Fixes: a6882431a138 ("media: iris: Add support for ENUM_FRAMESIZES/FRAMEINTERVALS for encoder")
Cc: [email protected]
Reviewed-by: Bryan O'Donoghue <[email protected]>
Signed-off-by: Vishnu Reddy <[email protected]>
---
 drivers/media/platform/qcom/iris/iris_vidc.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/media/platform/qcom/iris/iris_vidc.c b/drivers/media/platform/qcom/iris/iris_vidc.c
index fcbc60016bee..8f20cb281a93 100644
--- a/drivers/media/platform/qcom/iris/iris_vidc.c
+++ b/drivers/media/platform/qcom/iris/iris_vidc.c
@@ -438,14 +438,14 @@ static int iris_enum_frameintervals(struct file *filp, void *fh,
 	mbpf = NUM_MBS_PER_FRAME(fival->height, fival->width);
 	fps = DIV_ROUND_UP(core->iris_platform_data->max_core_mbps, mbpf);
 
-	fival->type = V4L2_FRMIVAL_TYPE_STEPWISE;
+	fival->type = V4L2_FRMIVAL_TYPE_CONTINUOUS;
 	fival->stepwise.min.numerator = 1;
 	fival->stepwise.min.denominator =
 			min_t(u32, fps, MAXIMUM_FPS);
 	fival->stepwise.max.numerator = 1;
 	fival->stepwise.max.denominator = 1;
 	fival->stepwise.step.numerator = 1;
-	fival->stepwise.step.denominator = MAXIMUM_FPS;
+	fival->stepwise.step.denominator = 1;
 
 	return 0;
 }

-- 
2.34.1