On Mon, 2017-10-02 at 11:23 +0100, Chris Wilson wrote: > Quoting Joonas Lahtinen (2017-10-02 11:03:30) > > On Sat, 2017-09-30 at 13:57 +0800, Weinan Li wrote: > > > Let GVT-g VM read the CSB and CSB write pointer from virtual HWSP, not all > > > the host support this feature, need to check the BIT(3) of caps in PVINFO. > > > > > > Signed-off-by: Weinan Li <weinan.z.li@xxxxxxxxx> > > > Cc: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> > > > > <SNIP> > > > > > @@ -396,6 +393,12 @@ static bool csb_force_mmio(struct drm_i915_private *i915) > > > if (intel_vtd_active()) > > > return true; > > > > > > + /* GVT emulation depends upon host kernel implementation, check > > > + * support capbility by reading PV INFO before access HWSP. > > > + */ > > > > The comment can be dropped completely, the code is self-descriptive. > > > > > +++ b/drivers/gpu/drm/i915/intel_lrc.c > > > @@ -722,7 +722,12 @@ static void intel_lrc_irq_handler(unsigned long data) > > > &engine->status_page.page_addr[I915_HWS_CSB_BUF0_INDEX]; > > > unsigned int head, tail; > > > > > > - /* However GVT emulation depends upon intercepting CSB mmio */ > > > + /* However GVT-g emulation depends upon host kernel > > > + * implementation, need to check support capbility by reading PV > > > + * INFO before access HWSP. Beside from this, another special > > > + * configuration may also need to force use mmio, like IOMMU > > > + * enabled. > > > + */ > > > > s/capbility/capability/ and please rephrase this to be a kerneldoc for > > csb_use_mmio at the declaration. > > This is not a description of how to use the function or even on how > csb_use_mmio work, this is why we want certain logic paths. Just a regular > old comment. That's why I asked to "rephrase" :) Anyway, it seems like there already is kerneldoc for the csb_use_mmio, so this comment can be dropped. Regards, Joonas -- Joonas Lahtinen Open Source Technology Center Intel Corporation _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
