Re: [PATCH 01/12] drm/i915: Don't trust CSR program memory contents

Imre Deak
2015-11-11T19:05:03Z

On ma, 2015-11-09 at 16:48 +0100, Patrik Jakobsson wrote:
> Replaces "drm/i915: Force loading of csr program at boot" in the old
> series.
>
> Previously we called blindly into intel_csr_load_program() and
> depended
> on a check of whether the CSR program memory was cleared or not.
> This check is not reliable and no longer needed since we fixed the
> call-sites of intel_csr_load_program().
>
> Signed-off-by: Patrik Jakobsson <patrik.jakobsson@linux.intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>

> ---
> drivers/gpu/drm/i915/intel_csr.c | 10 +++-------
> 1 file changed, 3 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_csr.c
> b/drivers/gpu/drm/i915/intel_csr.c
> index ecb7c70..ad8bc7a 100644
> --- a/drivers/gpu/drm/i915/intel_csr.c
> +++ b/drivers/gpu/drm/i915/intel_csr.c
> @@ -220,14 +220,10 @@ void intel_csr_load_program(struct
> drm_i915_private *dev_priv)
> return;
> }
>
> - /*
> - * FIXME: Firmware gets lost on S3/S4, but not when entering
> system
> - * standby or suspend-to-idle (which is just like forced
> runtime pm).
> - * Unfortunately the ACPI subsystem doesn't yet give us a
> way to
> - * differentiate this, hence figure it out with this hack.
> - */
> - if ((!dev_priv->csr.dmc_payload) ||
> I915_READ(CSR_PROGRAM(0)))
> + if (!dev_priv->csr.dmc_payload) {
> + DRM_ERROR("Tried to program CSR with empty
> payload\n");
> return;
> + }
>
> fw_size = dev_priv->csr.dmc_fw_size;
> for (i = 0; i < fw_size; i++)