| Message ID | 13745984973760@kroah.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, Jul 23, 2013 at 09:54:57AM -0700, gregkh@linuxfoundation.org wrote: > > The patch below does not apply to the 3.10-stable tree. You can drop it. The patch is already in 3.10 and it does not need to be backported to earlier trees. There was a snaffu were I thought David would post this in v3.11 merge window - hence the stable@vger.kernel.org tag. But David came in to rescue me and at the last minute sent an git pull to Linus for v3.10. So all good. Thanks! > If someone wants it applied there, or to any other stable or longterm > tree, then please email the backport, including the original git commit > id to <stable@vger.kernel.org>. > > thanks, > > greg k-h > > ------------------ original commit in Linus's tree ------------------ > > >From 1625e7e549c50fb57a1e1ab1cb0f5735c84c9029 Mon Sep 17 00:00:00 2001 > From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> > Date: Mon, 24 Jun 2013 11:47:48 -0400 > Subject: [PATCH] drm/i915: make compact dma scatter lists creation work with > SWIOTLB backend. > > Git commit 90797e6d1ec0dfde6ba62a48b9ee3803887d6ed4 > ("drm/i915: create compact dma scatter lists for gem objects") makes > certain assumptions about the under laying DMA API that are not always > correct. > > On a ThinkPad X230 with an Intel HD 4000 with Xen during the bootup > I see: > > [drm:intel_pipe_set_base] *ERROR* pin & fence failed > [drm:intel_crtc_set_config] *ERROR* failed to set mode on [CRTC:3], err = -28 > > Bit of debugging traced it down to dma_map_sg failing (in > i915_gem_gtt_prepare_object) as some of the SG entries were huge (3MB). > > That unfortunately are sizes that the SWIOTLB is incapable of handling - > the maximum it can handle is a an entry of 512KB of virtual contiguous > memory for its bounce buffer. (See IO_TLB_SEGSIZE). > > Previous to the above mention git commit the SG entries were of 4KB, and > the code introduced by above git commit squashed the CPU contiguous PFNs > in one big virtual address provided to DMA API. > > This patch is a simple semi-revert - were we emulate the old behavior > if we detect that SWIOTLB is online. If it is not online then we continue > on with the new compact scatter gather mechanism. > > An alternative solution would be for the the '.get_pages' and the > i915_gem_gtt_prepare_object to retry with smaller max gap of the > amount of PFNs that can be combined together - but with this issue > discovered during rc7 that might be too risky. > > Reported-and-Tested-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> > CC: Chris Wilson <chris@chris-wilson.co.uk> > CC: Imre Deak <imre.deak@intel.com> > CC: Daniel Vetter <daniel.vetter@ffwll.ch> > CC: David Airlie <airlied@linux.ie> > CC: <dri-devel@lists.freedesktop.org> > Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> > Cc: stable@vger.kernel.org > Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> > > diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c > index a6178bac..e31eeb1d 100644 > --- a/drivers/gpu/drm/i915/i915_gem.c > +++ b/drivers/gpu/drm/i915/i915_gem.c > @@ -1802,7 +1802,14 @@ i915_gem_object_get_pages_gtt(struct drm_i915_gem_object *obj) > gfp |= __GFP_NORETRY | __GFP_NOWARN | __GFP_NO_KSWAPD; > gfp &= ~(__GFP_IO | __GFP_WAIT); > } > - > +#ifdef CONFIG_SWIOTLB > + if (swiotlb_nr_tbl()) { > + st->nents++; > + sg_set_page(sg, page, PAGE_SIZE, 0); > + sg = sg_next(sg); > + continue; > + } > +#endif > if (!i || page_to_pfn(page) != last_pfn + 1) { > if (i) > sg = sg_next(sg); > @@ -1813,8 +1820,10 @@ i915_gem_object_get_pages_gtt(struct drm_i915_gem_object *obj) > } > last_pfn = page_to_pfn(page); > } > - > - sg_mark_end(sg); > +#ifdef CONFIG_SWIOTLB > + if (!swiotlb_nr_tbl()) > +#endif > + sg_mark_end(sg); > obj->pages = st; > > if (i915_gem_object_needs_bit17_swizzle(obj)) >
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index a6178bac..e31eeb1d 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -1802,7 +1802,14 @@ i915_gem_object_get_pages_gtt(struct drm_i915_gem_object *obj) gfp |= __GFP_NORETRY | __GFP_NOWARN | __GFP_NO_KSWAPD; gfp &= ~(__GFP_IO | __GFP_WAIT); } - +#ifdef CONFIG_SWIOTLB + if (swiotlb_nr_tbl()) { + st->nents++; + sg_set_page(sg, page, PAGE_SIZE, 0); + sg = sg_next(sg); + continue; + } +#endif if (!i || page_to_pfn(page) != last_pfn + 1) { if (i) sg = sg_next(sg); @@ -1813,8 +1820,10 @@ i915_gem_object_get_pages_gtt(struct drm_i915_gem_object *obj) } last_pfn = page_to_pfn(page); } - - sg_mark_end(sg); +#ifdef CONFIG_SWIOTLB + if (!swiotlb_nr_tbl()) +#endif + sg_mark_end(sg); obj->pages = st; if (i915_gem_object_needs_bit17_swizzle(obj))