drm/i915: Avoid use of uninitialised values when disabling panel-fitter
We were passing garbage values into the panel-fitter control register
when disabling it on Ironlake - those values (filter modes and reserved
MBZ bits) would have then be re-used the next time panel-fitting was
enabled.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 1bd0c67..cf8d5e5 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -1865,9 +1865,6 @@
int fdi_tx_reg = (pipe == 0) ? FDI_TXA_CTL : FDI_TXB_CTL;
int fdi_rx_reg = (pipe == 0) ? FDI_RXA_CTL : FDI_RXB_CTL;
int transconf_reg = (pipe == 0) ? TRANSACONF : TRANSBCONF;
- int pf_ctl_reg = (pipe == 0) ? PFA_CTL_1 : PFB_CTL_1;
- int pf_win_size = (pipe == 0) ? PFA_WIN_SZ : PFB_WIN_SZ;
- int pf_win_pos = (pipe == 0) ? PFA_WIN_POS : PFB_WIN_POS;
int cpu_htot_reg = (pipe == 0) ? HTOTAL_A : HTOTAL_B;
int cpu_hblank_reg = (pipe == 0) ? HBLANK_A : HBLANK_B;
int cpu_hsync_reg = (pipe == 0) ? HSYNC_A : HSYNC_B;
@@ -1936,15 +1933,19 @@
}
/* Enable panel fitting for LVDS */
- if (intel_pipe_has_type(crtc, INTEL_OUTPUT_LVDS)
- || HAS_eDP || intel_pch_has_edp(crtc)) {
- if (dev_priv->pch_pf_size) {
- temp = I915_READ(pf_ctl_reg);
- I915_WRITE(pf_ctl_reg, temp | PF_ENABLE | PF_FILTER_MED_3x3);
- I915_WRITE(pf_win_pos, dev_priv->pch_pf_pos);
- I915_WRITE(pf_win_size, dev_priv->pch_pf_size);
- } else
- I915_WRITE(pf_ctl_reg, temp & ~PF_ENABLE);
+ if (dev_priv->pch_pf_size &&
+ (intel_pipe_has_type(crtc, INTEL_OUTPUT_LVDS)
+ || HAS_eDP || intel_pch_has_edp(crtc))) {
+ /* Force use of hard-coded filter coefficients
+ * as some pre-programmed values are broken,
+ * e.g. x201.
+ */
+ I915_WRITE(pipe ? PFB_CTL_1 : PFA_CTL_1,
+ PF_ENABLE | PF_FILTER_MED_3x3);
+ I915_WRITE(pipe ? PFB_WIN_POS : PFA_WIN_POS,
+ dev_priv->pch_pf_pos);
+ I915_WRITE(pipe ? PFB_WIN_SZ : PFA_WIN_SZ,
+ dev_priv->pch_pf_size);
}
/* Enable CPU pipe */
@@ -2109,14 +2110,8 @@
udelay(100);
/* Disable PF */
- temp = I915_READ(pf_ctl_reg);
- if ((temp & PF_ENABLE) != 0) {
- I915_WRITE(pf_ctl_reg, temp & ~PF_ENABLE);
- I915_READ(pf_ctl_reg);
- }
- I915_WRITE(pf_win_size, 0);
- POSTING_READ(pf_win_size);
-
+ I915_WRITE(pipe ? PFB_CTL_1 : PFA_CTL_1, 0);
+ I915_WRITE(pipe ? PFB_WIN_SZ : PFA_WIN_SZ, 0);
/* disable CPU FDI tx and PCH FDI rx */
temp = I915_READ(fdi_tx_reg);