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

[Srivatsa, Anusha]

>-----Original Message-----
>From: Intel-gfx [mailto:intel-gfx-bounces at lists.freedesktop.org] On Behalf Of
>Jani Nikula
>Sent: Wednesday, November 22, 2017 8:20 AM
>To: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>; David Weinehall
><david.weinehall at linux.intel.com>
>Cc: intel-gfx at lists.freedesktop.org
>Subject: Re: [Intel-gfx] [PATCH] drm/i915: add support for specifying DMC
>firmware override by module param
>
>On Wed, 22 Nov 2017, Joonas Lahtinen <joonas.lahtinen at 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 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) \
>>
>> 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 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.

I believe this patch is going to be useful anyway.... IT would make things a lot easier for testing purpose. I think we should get this merged.

Does anyone have any concerns?

Anusha 
>>> 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
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