Messages in this thread Patch in this message | | | Date | Wed, 16 Dec 2009 19:57:15 -0800 | From | Greg KH <> | Subject | [138/151] drm/i915: Avoid NULL dereference with component_only tv_modes |
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2.6.32-stable review patch. If anyone has any objections, please let us know.
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From: Chris Wilson <chris@chris-wilson.co.uk>
commit d271817baecbccb47da0d9f28c285a0dae8a06b7 upstream.
In commit d2d9f2324, the guard for a valid video mode was removed. This caused the regression:
kernel crash during kms graphic boot on Intel GM4500 platform https://bugzilla.redhat.com/show_bug.cgi?id=540218
This patches changes the logic slightly not to rely on a coupled variable, but to just check whether the video_modes is valid before dereferencing.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Zhenyu Wang <zhenyu.z.wang@intel.com> [ickle: Actually reference the correct bug report] Acked-by: Zhenyu Wang <zhenyuw@linux.intel.com> Signed-off-by: Eric Anholt <eric@anholt.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
--- drivers/gpu/drm/i915/intel_tv.c | 11 ++++------- 1 file changed, 4 insertions(+), 7 deletions(-)
--- a/drivers/gpu/drm/i915/intel_tv.c +++ b/drivers/gpu/drm/i915/intel_tv.c @@ -1213,20 +1213,17 @@ intel_tv_mode_set(struct drm_encoder *en tv_ctl |= TV_TRILEVEL_SYNC; if (tv_mode->pal_burst) tv_ctl |= TV_PAL_BURST; + scctl1 = 0; - /* dda1 implies valid video levels */ - if (tv_mode->dda1_inc) { + if (tv_mode->dda1_inc) scctl1 |= TV_SC_DDA1_EN; - } - if (tv_mode->dda2_inc) scctl1 |= TV_SC_DDA2_EN; - if (tv_mode->dda3_inc) scctl1 |= TV_SC_DDA3_EN; - scctl1 |= tv_mode->sc_reset; - scctl1 |= video_levels->burst << TV_BURST_LEVEL_SHIFT; + if (video_levels) + scctl1 |= video_levels->burst << TV_BURST_LEVEL_SHIFT; scctl1 |= tv_mode->dda1_inc << TV_SCDDA1_INC_SHIFT; scctl2 = tv_mode->dda2_size << TV_SCDDA2_SIZE_SHIFT |
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