From: Chris Wilson Date: Sun, 24 May 2020 23:39:00 +0000 (+0100) Subject: drm/i915/display: Fix early deref of 'dsb' X-Git-Tag: v5.15~3115^2~24^2~151 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=6f081dbfdd4e54d50161c437f2cea176384501d9;p=platform%2Fkernel%2Flinux-starfive.git drm/i915/display: Fix early deref of 'dsb' drivers/gpu/drm/i915/display/intel_dsb.c:177 intel_dsb_reg_write() warn: variable dereferenced before check 'dsb' (see line 175) Fixes: afeda4f3b1c8 ("drm/i915/dsb: Pre allocate and late cleanup of cmd buffer") Signed-off-by: Chris Wilson Cc: Ville Syrjälä Cc: Animesh Manna Cc: Uma Shankar Reviewed-by: Animesh Manna Link: https://patchwork.freedesktop.org/patch/msgid/20200524233900.25598-1-chris@chris-wilson.co.uk --- diff --git a/drivers/gpu/drm/i915/display/intel_dsb.c b/drivers/gpu/drm/i915/display/intel_dsb.c index 475106e..24e6d63 100644 --- a/drivers/gpu/drm/i915/display/intel_dsb.c +++ b/drivers/gpu/drm/i915/display/intel_dsb.c @@ -169,15 +169,17 @@ void intel_dsb_indexed_reg_write(const struct intel_crtc_state *crtc_state, void intel_dsb_reg_write(const struct intel_crtc_state *crtc_state, i915_reg_t reg, u32 val) { - struct intel_dsb *dsb = crtc_state->dsb; struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc); struct drm_i915_private *dev_priv = to_i915(crtc->base.dev); - u32 *buf = dsb->cmd_buf; + struct intel_dsb *dsb; + u32 *buf; + dsb = crtc_state->dsb; if (!dsb) { intel_de_write(dev_priv, reg, val); return; } + buf = dsb->cmd_buf; if (drm_WARN_ON(&dev_priv->drm, dsb->free_pos >= DSB_BUF_SIZE)) { drm_dbg_kms(&dev_priv->drm, "DSB buffer overflow\n");