Reviewing the dotclock computation from the refclk and dividers is a very useful step in manually checking the register configuration.
Signed-off-by: Chris Wilson <[email protected]> --- drivers/gpu/drm/i915/intel_display.c | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index e2e2173..1333a56 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -4844,6 +4844,19 @@ static void i9xx_set_pipeconf(struct intel_crtc *intel_crtc) POSTING_READ(PIPECONF(intel_crtc->pipe)); } +static u64 compute_dotclock(int refclk, const intel_clock_t *clock) +{ + u64 dotclock; + + dotclock = refclk; + dotclock *= 5 * (clock->m1 + 2) + clock->m2 + 2; + do_div(dotclock, 2+clock->n); + do_div(dotclock, clock->p1); + do_div(dotclock, clock->p2); + + return dotclock; +} + static int i9xx_crtc_mode_set(struct drm_crtc *crtc, int x, int y, struct drm_framebuffer *fb) @@ -4888,6 +4901,10 @@ static int i9xx_crtc_mode_set(struct drm_crtc *crtc, DRM_ERROR("Couldn't find PLL settings for mode!\n"); return -EINVAL; } + DRM_DEBUG_KMS("refclk=%d, clock=(.m1=%d, .m2=%d, n=%d, .p1=%d, .p2=%d), computed dotclock = %lld\n", + refclk, clock.m1, clock.m2, clock.n, clock.p1, clock.p2, + compute_dotclock(refclk, &clock)); + /* Ensure that the cursor is valid for the new mode before changing... */ intel_crtc_update_cursor(crtc, true); @@ -5736,6 +5753,12 @@ static int ironlake_crtc_mode_set(struct drm_crtc *crtc, DRM_ERROR("Couldn't find PLL settings for mode!\n"); return -EINVAL; } + + DRM_DEBUG_KMS("refclk=%d, clock=(.m1=%d, .m2=%d, n=%d, .p1=%d, .p2=%d), computed dotclock = %lld\n", + ironlake_get_refclk(crtc), + clock.m1, clock.m2, clock.n, clock.p1, clock.p2, + compute_dotclock(ironlake_get_refclk(crtc), &clock)); + /* Compat-code for transition, will disappear. */ if (!intel_crtc->config.clock_set) { intel_crtc->config.dpll.n = clock.n; -- 1.7.10.4 _______________________________________________ Intel-gfx mailing list [email protected] http://lists.freedesktop.org/mailman/listinfo/intel-gfx
