drm/vc4: plane: TPZ scaling modes cannot reduce lbm size when alpha-less #7164
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This code can never do anything, as channels_scaled can only be 0 or 2. I suspect that the index was intended to be i rather than channel, but that would trigger for scaled RGB planes, and halving lines is not wanted there. Just remove it. Signed-off-by: Dom Cobley <popcornmix@gmail.com>
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Nit pick over the comment, but I'm happy with this change.
Nasty that they tucked the comment about there not being a non-alpha TPZ mode into one of the examples :-(
drivers/gpu/drm/vc4/vc4_plane.c
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| if (info->has_alpha) | ||
| // spec says "Note that there is not an extra mode to save memory | ||
| // for alpha-less formats" in the TPZ section |
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The commit text is sufficient via git blame, so no need for this comment that checkpatch complain had about the length of, and is now a multi-line using // (should be /* */).
spec says "Note that there is not an extra mode to save memory for alpha-less formats" in the TPZ section. Currently, if first plane is RGB888 and scaled down (TPZ) a second plane will corrupt the LBM and result in garbage I've also folded in the modification to components to the function as it seems misplaced Signed-off-by: Dom Cobley <popcornmix@gmail.com>
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Indeed. It was well hidden away. Removed the comment. |
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@pelwell any objection? |
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None from me - when I looked yesterday the auto-builds were still active. I wish GitHub had a "Merge when it passes" button. |
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kernel: media: i2c: imx477: Correct IMX477_REG_TEST_PATTERN to be 16bit See: raspberrypi/linux#7162 kernel: dtoverlay for Ilitek 23XX, 25XX, and 213X touch controllers See: raspberrypi/linux#7146 kernel: drm/vc4: plane: TPZ scaling modes cannot reduce lbm size when alpha-less See: raspberrypi/linux#7164
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kernel: media: i2c: imx477: Correct IMX477_REG_TEST_PATTERN to be 16bit See: raspberrypi/linux#7162 kernel: dtoverlay for Ilitek 23XX, 25XX, and 213X touch controllers See: raspberrypi/linux#7146 kernel: drm/vc4: plane: TPZ scaling modes cannot reduce lbm size when alpha-less See: raspberrypi/linux#7164
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Spec says "Note that there is not an extra mode to save memory for alpha-less formats" in the TPZ section.
Curently, if first plane is RGB888 and scaled down (TPZ) a second plane will corrupt the LBM and result in garbage
I've also folded in the modification to components to the function as it seems misplaced