[Intel-gfx] [PATCH 4/8] drm/i915/huc: Add BXT HuC Loading Support

[Jeff McGee]

On Mon, Dec 05, 2016 at 12:42:11PM -0800, Srivatsa, Anusha wrote:
> 
> 
> >-----Original Message-----
> >From: Tvrtko Ursulin [mailto:tvrtko.ursulin at linux.intel.com]
> >Sent: Thursday, December 1, 2016 5:11 AM
> >To: Srivatsa, Anusha <anusha.srivatsa at intel.com>; intel-
> >gfx at lists.freedesktop.org
> >Subject: Re: [Intel-gfx] [PATCH 4/8] drm/i915/huc: Add BXT HuC Loading Support
> >
> >
> >On 30/11/2016 23:31, Anusha Srivatsa wrote:
> >> This patch adds the HuC Loading for the BXT by using the updated file
> >> construction.
> >>
> >> Version 1.7 of the HuC firmware.
> >>
> >> v2: rebased.
> >> v3: rebased on top of drm-tip
> >>
> >> Cc: Jeff Mcgee <jeff.mcgee at intel.com>
> >> Signed-off-by: Anusha Srivatsa <anusha.srivatsa at intel.com>
> >> Reviewed-by: Jeff McGee <jeff.mcgee at intel.com>
> >> ---
> >>  drivers/gpu/drm/i915/intel_huc_loader.c | 11 +++++++++++
> >>  1 file changed, 11 insertions(+)
> >>
> >> diff --git a/drivers/gpu/drm/i915/intel_huc_loader.c
> >> b/drivers/gpu/drm/i915/intel_huc_loader.c
> >> index 663fcc4..6357c19 100644
> >> --- a/drivers/gpu/drm/i915/intel_huc_loader.c
> >> +++ b/drivers/gpu/drm/i915/intel_huc_loader.c
> >> @@ -40,6 +40,10 @@
> >>   * Note that HuC firmware loading must be done before GuC loading.
> >>   */
> >>
> >> +#define BXT_FW_MAJOR 01
> >> +#define BXT_FW_MINOR 07
> >> +#define BXT_BLD_NUM 1398
> >> +
> >>  #define SKL_FW_MAJOR 01
> >>  #define SKL_FW_MINOR 07
> >>  #define SKL_BLD_NUM 1398
> >> @@ -52,6 +56,9 @@
> >>  	SKL_FW_MINOR, SKL_BLD_NUM)
> >>  MODULE_FIRMWARE(I915_SKL_HUC_UCODE);
> >>
> >> +#define I915_BXT_HUC_UCODE HUC_FW_PATH(bxt, BXT_FW_MAJOR, \
> >> +	BXT_FW_MINOR, BXT_BLD_NUM)
> >> +MODULE_FIRMWARE(I915_BXT_HUC_UCODE);
> >>  /**
> >>   * huc_ucode_xfer() - DMA's the firmware
> >>   * @dev_priv: the drm device
> >> @@ -159,6 +166,10 @@ void intel_huc_init(struct drm_device *dev)
> >>  		fw_path = I915_SKL_HUC_UCODE;
> >>  		huc_fw->major_ver_wanted = SKL_FW_MAJOR;
> >>  		huc_fw->minor_ver_wanted = SKL_FW_MINOR;
> >> +	} else if (IS_BROXTON(dev_priv)) {
> >> +		fw_path = I915_BXT_HUC_UCODE;
> >> +		huc_fw->major_ver_wanted = BXT_FW_MAJOR;
> >> +		huc_fw->minor_ver_wanted = BXT_FW_MINOR;
> >>  	}
> >>
> >>  	huc_fw->uc_fw_path = fw_path;
> >>
> >
> >Build number in the file name still worries me. Last time I've asked about it the
> >thread kind of died off so I will re-state it.
> >
> >My concern is that if we will be getting firmware releases with the same major-
> >minor but different build numbers, then embedding the build number into the
> >driver prevents loading of a newer firmware unless the kernel is also updated.
> >
> >I am not sure if that is what we want. Perhaps it is not expected at all that will
> >happen in production so it is not a concern?
> >
> >Or if it could happen, perhaps we should either push back on the scheme
> >- drop the build number and bump the minor in all cases, or alternatively for our
> >purposes drop the build number from the driver and have a symlinked scheme on
> >disk?
> >
> >Regards,
> >
> >Tvrtko
> 
> Hi Tvrtko,
> Sincere apologies for responding so late. According to my understanding, Jeff correct me if I am wrong, we are finalizing the firmware version number for every kernel version. So a certain kernel will have only one possible firware major-minor and build number for a certain platform.
> 
>  I have cc-ed Jeff in this thread so he can add his comment on build number. Jeff, any comments?
> 
> Regards,
> Anusha

Sorry for delayed response. I'm checking with HuC firmware team on their
intended release model.
-Jeff