drm/i915: Warn if a pipe is enabled with a bogus port
If TRANS_DDI_FUNC_CTL has been wrongly programmed with an incorrect
port, we are currently trying to read PORT_CLK_SEL(port) with an
uninitialized value.
Handle that case by returning PORT_CLK_SEL_NONE and warning about it.
v2: Move the warning inside intel_ddi_get_crtc_pll (Paulo Zanoni)
Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>
Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
index d26147c..258e38e 100644
--- a/drivers/gpu/drm/i915/intel_ddi.c
+++ b/drivers/gpu/drm/i915/intel_ddi.c
@@ -1160,7 +1160,7 @@
enum pipe pipe)
{
uint32_t temp, ret;
- enum port port;
+ enum port port = I915_MAX_PORTS;
enum transcoder cpu_transcoder = intel_pipe_to_cpu_transcoder(dev_priv,
pipe);
int i;
@@ -1176,10 +1176,16 @@
port = i;
}
- ret = I915_READ(PORT_CLK_SEL(port));
-
- DRM_DEBUG_KMS("Pipe %c connected to port %c using clock 0x%08x\n",
- pipe_name(pipe), port_name(port), ret);
+ if (port == I915_MAX_PORTS) {
+ WARN(1, "Pipe %c enabled on an unknown port\n",
+ pipe_name(pipe));
+ ret = PORT_CLK_SEL_NONE;
+ } else {
+ ret = I915_READ(PORT_CLK_SEL(port));
+ DRM_DEBUG_KMS("Pipe %c connected to port %c using clock "
+ "0x%08x\n", pipe_name(pipe), port_name(port),
+ ret);
+ }
return ret;
}
