On 28/07/15 14:27, Chris Wilson wrote:
> Since we already return -EFAULT to the user, emitting an error message
> *and* WARN is overkill. If the caller is upset, they can do so, but for
> the purposes of debugging we need only log the erroneous values.
>
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc:: Alex Dai <yu.dai at intel.com>
> Cc: Dave Gordon <david.s.gordon at intel.com>
> Cc: Tom O'Rourke <Tom.O'Rourke at intel.com>
> ---
> drivers/gpu/drm/i915/i915_gem.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
> index c1ded76a6eb4..2039798f4403 100644
> --- a/drivers/gpu/drm/i915/i915_gem.c
> +++ b/drivers/gpu/drm/i915/i915_gem.c
> @@ -5243,8 +5243,8 @@ i915_gem_object_create_from_data(struct drm_device *dev,
>
> i915_gem_object_unpin_pages(obj);
>
> - if (WARN_ON(bytes != size)) {
> - DRM_ERROR("Incomplete copy, wrote %zu of %zu", bytes, size);
> + if (bytes != size) {
> + DRM_DEBUG_GEM("Incomplete copy, wrote %zu of %zu", bytes, size);
> ret = -EFAULT;
> goto fail;
> }
I agree the WARN_ON() is overkill, but I think maybe the DRM_ERROR() is
useful. The (one current) caller will report an error, but at that level
it's just:
DRM_ERROR("Failed to fetch GuC firmware from %s\n", ...)
with no more detail as to whether that was due to file-not-found,
bad-file-size, out-of-memory, failed-to-get-pages, or any of the other
errors that might arise.
At present this code is only called once, and I think this copy failure
"shouldn't ever happen", so it won't be filling the logfile. But
emitting the error here for the truly unexpected case (as opposed to the
commonplace "out-of-memory" and suchlike) helps current and future
callers avoid doing the detailed failure analysis.
Or maybe it's a good place for your (other) new macro?
DRM_NOTICE_ON(bytes != size,
"Incomplete copy, wrote %zu of %zu", bytes, size);
.Dave.
