01.02.2019 16:28, Thierry Reding пишет: > From: Thierry Reding <treding@xxxxxxxxxx> > > The HOST1X_CHANNEL_DMAEND is an offset relative to the value written to > the HOST1X_CHANNEL_DMASTART register, but it is currently treated as an > absolute address. This can cause SMMU faults if the CDMA fetches past a > pushbuffer's IOMMU mapping. > > Properly setting the DMAEND prevents the CDMA from fetching beyond that > address and avoid such issues. This is currently not observed because a > whole (almost) page of essentially scratch space absorbs any excessive > prefetching by CDMA. However, changing the number of slots in the push > buffer can trigger these SMMU faults. > > Signed-off-by: Thierry Reding <treding@xxxxxxxxxx> > --- > drivers/gpu/host1x/hw/cdma_hw.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/host1x/hw/cdma_hw.c b/drivers/gpu/host1x/hw/cdma_hw.c > index 485aef5761af..a24c090ac96f 100644 > --- a/drivers/gpu/host1x/hw/cdma_hw.c > +++ b/drivers/gpu/host1x/hw/cdma_hw.c > @@ -75,7 +75,7 @@ static void cdma_start(struct host1x_cdma *cdma) > > cdma->last_pos = cdma->push_buffer.pos; > start = cdma->push_buffer.dma; > - end = start + cdma->push_buffer.size + 4; > + end = cdma->push_buffer.size + 4; > > host1x_ch_writel(ch, HOST1X_CHANNEL_DMACTRL_DMASTOP, > HOST1X_CHANNEL_DMACTRL); > @@ -126,7 +126,7 @@ static void cdma_timeout_restart(struct host1x_cdma *cdma, u32 getptr) > HOST1X_CHANNEL_DMACTRL); > > start = cdma->push_buffer.dma; > - end = start + cdma->push_buffer.size + 4; > + end = cdma->push_buffer.size + 4; > > /* set base, end pointer (all of memory) */ > host1x_ch_writel(ch, lower_32_bits(start), HOST1X_CHANNEL_DMASTART); > Reviewed-by: Dmitry Osipenko <digetx@xxxxxxxxx> Tested-by: Dmitry Osipenko <digetx@xxxxxxxxx> _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
