[Intel-gfx] [PATCH] drm/i915: add support for specifying DMC firmware override by module param

[David Weinehall]

On Tue, Nov 21, 2017 at 11:54:16PM +0200, Jani Nikula wrote:
> On Tue, 21 Nov 2017, David Weinehall <david.weinehall at linux.intel.com> wrote:
> > On Tue, Nov 21, 2017 at 01:51:29PM +0200, Jani Nikula wrote:
> >> Use i915.dmc_firmware_path to override default firmware for the platform
> >> and bypassing version checks.
> >> 
> >> Signed-off-by: Jani Nikula <jani.nikula at intel.com>
> >> 
> >> ---
> >> 
> >> Untested.
> >
> > Yeah, it kind of shows.  It fails to compile :D
> 
> Oops. I was anxious to get the patch on the list in the heat of IRC
> discussion, and just added the disclaimer instead of doing this
> properly... *blush*
> 
> >
> > But if you chuck in:
> >
> >         param(char *, dmc_firmware_path, NULL) \
> >
> > in i915_params.h
> >
> > Things work correctly and you can use:
> >
> > Tested-by: David Weinehall <david.weinehall at linux.intel.com>
> > Reviewed-by: David Weinehall <david.weinehall at linux.intel.com>
> 
> Thanks. But let's wait for more input on whether this is really what
> people want. Perhaps this is useful *regardless* of the outcome of the
> other discussions.

Fine by me. FWIW *we* (as in the PnP testing team) would definitely
benefit if this patch got merged, since we'd be able to simplify
automated testing of different versions of DMC.

> BR,
> Jani.
> 
> 
> >
> >> ---
> >>  drivers/gpu/drm/i915/i915_params.c | 3 +++
> >>  drivers/gpu/drm/i915/intel_csr.c   | 9 +++++++--
> >>  2 files changed, 10 insertions(+), 2 deletions(-)
> >> 
> >> diff --git a/drivers/gpu/drm/i915/i915_params.c b/drivers/gpu/drm/i915/i915_params.c
> >> index 3328147b4863..c11ad6d67fa9 100644
> >> --- a/drivers/gpu/drm/i915/i915_params.c
> >> +++ b/drivers/gpu/drm/i915/i915_params.c
> >> @@ -171,6 +171,9 @@ i915_param_named_unsafe(guc_firmware_path, charp, 0400,
> >>  i915_param_named_unsafe(huc_firmware_path, charp, 0400,
> >>  	"HuC firmware path to use instead of the default one");
> >>  
> >> +i915_param_named_unsafe(dmc_firmware_path, charp, 0400,
> >> +	"DMC firmware path to use instead of the default one");
> >> +
> >>  i915_param_named_unsafe(enable_dp_mst, bool, 0600,
> >>  	"Enable multi-stream transport (MST) for new DisplayPort sinks. (default: true)");
> >>  
> >> diff --git a/drivers/gpu/drm/i915/intel_csr.c b/drivers/gpu/drm/i915/intel_csr.c
> >> index 77d8b3d483ca..82db376ec7e1 100644
> >> --- a/drivers/gpu/drm/i915/intel_csr.c
> >> +++ b/drivers/gpu/drm/i915/intel_csr.c
> >> @@ -296,7 +296,10 @@ static uint32_t *parse_csr_fw(struct drm_i915_private *dev_priv,
> >>  
> >>  	csr->version = css_header->version;
> >>  
> >> -	if (IS_CANNONLAKE(dev_priv)) {
> >> +	if (csr->fw_path == i915_modparams.dmc_firmware_path) {
> >> +		/* Bypass version check for firmware override. */
> >> +		required_version = csr->version;
> >> +	} else if (IS_CANNONLAKE(dev_priv)) {
> >>  		required_version = CNL_CSR_VERSION_REQUIRED;
> >>  	} else if (IS_GEMINILAKE(dev_priv)) {
> >>  		required_version = GLK_CSR_VERSION_REQUIRED;
> >> @@ -451,7 +454,9 @@ void intel_csr_ucode_init(struct drm_i915_private *dev_priv)
> >>  	if (!HAS_CSR(dev_priv))
> >>  		return;
> >>  
> >> -	if (IS_CANNONLAKE(dev_priv))
> >> +	if (i915_modparams.dmc_firmware_path)
> >> +		csr->fw_path = i915_modparams.dmc_firmware_path;
> >> +	else if (IS_CANNONLAKE(dev_priv))
> >>  		csr->fw_path = I915_CSR_CNL;
> >>  	else if (IS_GEMINILAKE(dev_priv))
> >>  		csr->fw_path = I915_CSR_GLK;
> >> -- 
> >> 2.11.0
> >> 
> >> _______________________________________________
> >> Intel-gfx mailing list
> >> Intel-gfx at lists.freedesktop.org
> >> https://lists.freedesktop.org/mailman/listinfo/intel-gfx
> 
> -- 
> Jani Nikula, Intel Open Source Technology Center