On Fri, 25 Jan 2013 18:57:40 -0200
Paulo Zanoni <przanoni at gmail.com> wrote:
> From: Paulo Zanoni <paulo.r.zanoni at intel.com>
>
> While debugging these "unclaimed register" problems I concluded that
> having a backtrace is way much more useful than having the register
> address, since in a lot of cases the register address print on the
> message is not the register we're looking for.
>
> We must fix all the "unclaimed register" problems, so if dmesg gets
> too polluted it means we're too bugged.
>
> Signed-off-by: Paulo Zanoni <paulo.r.zanoni at intel.com>
As I mentioned internally, I'd still prefer
if (WARN_ON(I915_READ_NOTRACE(FPGA_DBG) & FPGA_DBG_RM_NOCLAIM))
because I don't think the message is particularly useful with a
backtrace in hand.
Also on second thought since the internal review, it's probably not
super useful to have the WARN in the UNCLAIMED_REG_CLEAR, because as
you've mentioned before, it's usually from snd-hda or something like
that. So I'd probably get rid of that unless someone else sees a super
cool usage for it.
With or without painting my color:
Reviewed-by: Ben Widawsky <ben at bwidawsk.net>
> ---
> drivers/gpu/drm/i915/i915_drv.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
> index 422dfc6..bc0eb88 100644
> --- a/drivers/gpu/drm/i915/i915_drv.c
> +++ b/drivers/gpu/drm/i915/i915_drv.c
> @@ -1227,14 +1227,14 @@ ilk_dummy_write(struct drm_i915_private *dev_priv)
> #define UNCLAIMED_REG_CLEAR(dev_priv, reg, op) \
> if (IS_HASWELL(dev_priv->dev) && \
> (I915_READ_NOTRACE(FPGA_DBG) & FPGA_DBG_RM_NOCLAIM)) { \
> - DRM_ERROR("Unclaimed register before %x (%c)\n", reg, op); \
> + WARN(1, "Unclaimed register before %x (%c)\n", reg, op); \
> I915_WRITE_NOTRACE(FPGA_DBG, FPGA_DBG_RM_NOCLAIM); \
> }
>
> #define UNCLAIMED_REG_CHECK(dev_priv, reg, op) \
> if (IS_HASWELL(dev_priv->dev) && \
> (I915_READ_NOTRACE(FPGA_DBG) & FPGA_DBG_RM_NOCLAIM)) { \
> - DRM_ERROR("Unclaimed register %x (%c)\n", reg, op); \
> + WARN(1, "Unclaimed register %x (%c)\n", reg, op); \
> I915_WRITE_NOTRACE(FPGA_DBG, FPGA_DBG_RM_NOCLAIM); \
> }
>
--
Ben Widawsky, Intel Open Source Technology Center
