This patch fixes two issues: - A disabled crtc does not use any lb, so return 0 for lb size. This makes the display priority calculation more exact. - Only use 1/2 and whole lb partitions. Using smaller partitions can cause underflow to one of the displays if you have multiple large displays on the same lb.
Fixes: https://bugs.freedesktop.org/show_bug.cgi?id=34534
Signed-off-by: Alex Deucher alexdeucher@gmail.com --- drivers/gpu/drm/radeon/evergreen.c | 89 ++++++++++++++++++------------------ 1 files changed, 44 insertions(+), 45 deletions(-)
diff --git a/drivers/gpu/drm/radeon/evergreen.c b/drivers/gpu/drm/radeon/evergreen.c index 5f057b8..11d1578 100644 --- a/drivers/gpu/drm/radeon/evergreen.c +++ b/drivers/gpu/drm/radeon/evergreen.c @@ -371,7 +371,7 @@ static u32 evergreen_line_buffer_adjust(struct radeon_device *rdev, struct drm_display_mode *mode, struct drm_display_mode *other_mode) { - u32 tmp = 0; + u32 tmp; /* * Line Buffer Setup * There are 3 line buffers, each one shared by 2 display controllers. @@ -381,64 +381,63 @@ static u32 evergreen_line_buffer_adjust(struct radeon_device *rdev, * first display controller * 0 - first half of lb (3840 * 2) * 1 - first 3/4 of lb (5760 * 2) - * 2 - whole lb (7680 * 2) + * 2 - whole lb (7680 * 2), other crtc must be disabled * 3 - first 1/4 of lb (1920 * 2) * second display controller * 4 - second half of lb (3840 * 2) * 5 - second 3/4 of lb (5760 * 2) - * 6 - whole lb (7680 * 2) + * 6 - whole lb (7680 * 2), other crtc must be disabled * 7 - last 1/4 of lb (1920 * 2) */ - if (mode && other_mode) { - if (mode->hdisplay > other_mode->hdisplay) { - if (mode->hdisplay > 2560) - tmp = 1; /* 3/4 */ - else - tmp = 0; /* 1/2 */ - } else if (other_mode->hdisplay > mode->hdisplay) { - if (other_mode->hdisplay > 2560) - tmp = 3; /* 1/4 */ - else - tmp = 0; /* 1/2 */ - } else + /* this can get tricky if we have two large displays on a paired group + * of crtcs. Ideally for multiple large displays we'd assign them to + * non-linked crtcs for maximum line buffer allocation. + */ + if (radeon_crtc->base.enabled && mode) { + if (other_mode) tmp = 0; /* 1/2 */ - } else if (mode) - tmp = 2; /* whole */ - else if (other_mode) - tmp = 3; /* 1/4 */ + else + tmp = 2; /* whole */ + } else + tmp = 0;
/* second controller of the pair uses second half of the lb */ if (radeon_crtc->crtc_id % 2) tmp += 4; WREG32(DC_LB_MEMORY_SPLIT + radeon_crtc->crtc_offset, tmp);
- switch (tmp) { - case 0: - case 4: - default: - if (ASIC_IS_DCE5(rdev)) - return 4096 * 2; - else - return 3840 * 2; - case 1: - case 5: - if (ASIC_IS_DCE5(rdev)) - return 6144 * 2; - else - return 5760 * 2; - case 2: - case 6: - if (ASIC_IS_DCE5(rdev)) - return 8192 * 2; - else - return 7680 * 2; - case 3: - case 7: - if (ASIC_IS_DCE5(rdev)) - return 2048 * 2; - else - return 1920 * 2; + if (radeon_crtc->base.enabled && mode) { + switch (tmp) { + case 0: + case 4: + default: + if (ASIC_IS_DCE5(rdev)) + return 4096 * 2; + else + return 3840 * 2; + case 1: + case 5: + if (ASIC_IS_DCE5(rdev)) + return 6144 * 2; + else + return 5760 * 2; + case 2: + case 6: + if (ASIC_IS_DCE5(rdev)) + return 8192 * 2; + else + return 7680 * 2; + case 3: + case 7: + if (ASIC_IS_DCE5(rdev)) + return 2048 * 2; + else + return 1920 * 2; + } } + + /* controller not enabled, so no lb used */ + return 0; }
static u32 evergreen_get_number_of_dram_channels(struct radeon_device *rdev)