On Thu, Mar 07, 2013 at 03:30:25PM +0000, Damien Lespiau wrote:
> Our static analysis tool noticed that 'reg' could be used uninitialized if
> we are trying to get a PLL to drive VGA and SPLL is already in use
> (plls->spll_refcoung != 0).
>
> In the (error) case above, let's return false to the caller and emit an
> error.
>
> Signed-off-by: Damien Lespiau <damien.lespiau at intel.com>
> ---
> drivers/gpu/drm/i915/intel_ddi.c | 3 +++
> 1 files changed, 3 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
> index a1505e3..0eab200 100644
> --- a/drivers/gpu/drm/i915/intel_ddi.c
> +++ b/drivers/gpu/drm/i915/intel_ddi.c
> @@ -898,6 +898,9 @@ bool intel_ddi_pll_mode_set(struct drm_crtc *crtc, int clock)
> plls->spll_refcount++;
> reg = SPLL_CTL;
> intel_crtc->ddi_pll_sel = PORT_CLK_SEL_SPLL;
> + } else {
> + DRM_ERROR("SPLL already in use\n");
> + return false;
> }
>
> WARN(I915_READ(reg) & SPLL_PLL_ENABLE,
I know very little about this code, but the warning still seems valuable
to me.
How about instead of else, move the reg = SPLL_CTL above the 'if'
--
Ben Widawsky, Intel Open Source Technology Center
