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

[Jani Nikula <jani.nikula@intel.com>]

On Wed, 22 Nov 2017, Joonas Lahtinen <joonas.lahtinen@linux.intel.com> wrote:
> On Tue, 2017-11-21 at 23:54 +0200, Jani Nikula wrote:
>> On Tue, 21 Nov 2017, David Weinehall <david.weinehall@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@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) \
>
> I think I already raised my suggestion earlier, but here it goes again.
> Maybe we should consider consolidating these into:
>
> i915.firmware=guc:whatever.bin i915.firmware=dmc:whatever.bin

I don't think that's possible. I didn't double check but I think you
only get one value from the module param code. Unless you roll your own
modparam hooks, which is best avoided.

> Then something like "i915.firmware=guc:disable" could be supported,
> too.

i915.dmc_firmware_path="" could mean disable.

BR,
Jani.


>
> Regards, Joonas
>
>> > 
>> > in i915_params.h
>> > 
>> > Things work correctly and you can use:
>> > 
>> > Tested-by: David Weinehall <david.weinehall@linux.intel.com>
>> > Reviewed-by: David Weinehall <david.weinehall@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.
>> 
>> 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@lists.freedesktop.org
>> > > https://lists.freedesktop.org/mailman/listinfo/intel-gfx
>> 
>> 

-- 
Jani Nikula, Intel Open Source Technology Center
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