| Message ID | 20170714143801.21535-1-l.stach@pengutronix.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Friday, July 14, 2017 7:38:01 AM PDT Lucas Stach wrote: > While this is no build dependency, etnaviv will only work correctly on most > systems if CMA and DMA_CMA are enabled. Select both options if available to > avoid users ending up with a non-working GPU due to a lacking kernel config. > > Signed-off-by: Lucas Stach <l.stach@pengutronix.de> > --- > drivers/gpu/drm/etnaviv/Kconfig | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/gpu/drm/etnaviv/Kconfig > b/drivers/gpu/drm/etnaviv/Kconfig index 71cee4e9fefb..38b477b5fbf9 100644 > --- a/drivers/gpu/drm/etnaviv/Kconfig > +++ b/drivers/gpu/drm/etnaviv/Kconfig > @@ -10,6 +10,8 @@ config DRM_ETNAVIV > select IOMMU_API > select IOMMU_SUPPORT > select WANT_DEV_COREDUMP > + select CMA if HAVE_DMA_CONTIGUOUS > + select DMA_CMA if HAVE_DMA_CONTIGUOUS > help > DRM driver for Vivante GPUs. IIRC, This at least half solves it. Does the user of systems with > 2 GiB need to explicitly specify cma size for it to work?
On Fri, Jul 14, 2017 at 04:38:01PM +0200, Lucas Stach wrote: > While this is no build dependency, etnaviv will only work correctly on most > systems if CMA and DMA_CMA are enabled. Select both options if available to > avoid users ending up with a non-working GPU due to a lacking kernel config. How does merely selecting CMA solve this problem? Does CMA guarantee that GPU command buffers will always be allocated in the lower 2G of physical address space? I suspect that's what you hope will happen, rather than a guarantee.
Am Sonntag, den 16.07.2017, 16:29 +0100 schrieb Russell King - ARM Linux: > On Fri, Jul 14, 2017 at 04:38:01PM +0200, Lucas Stach wrote: > > While this is no build dependency, etnaviv will only work correctly on most > > systems if CMA and DMA_CMA are enabled. Select both options if available to > > avoid users ending up with a non-working GPU due to a lacking kernel config. > > How does merely selecting CMA solve this problem? Does CMA guarantee > that GPU command buffers will always be allocated in the lower 2G of > physical address space? No, but CMA guarantees that commandbuffers will be allocated from the region and with the default CMA configuration dma_get_required_mask() will return the correct location of the CMA area, so we can move the linear memory window accordingly. There are no guarantees, but at least with a CMA area no larger than 2GB things will work for the average user, which is a lot better than leaving them with a non-working GPU due to a simple missing kernel configuration option. Regards, Lucas
Am Freitag, den 14.07.2017, 11:32 -0700 schrieb Joshua Clayton: > On Friday, July 14, 2017 7:38:01 AM PDT Lucas Stach wrote: > > While this is no build dependency, etnaviv will only work correctly on most > > systems if CMA and DMA_CMA are enabled. Select both options if available to > > avoid users ending up with a non-working GPU due to a lacking kernel config. > > > > Signed-off-by: Lucas Stach <l.stach@pengutronix.de> > > --- > > drivers/gpu/drm/etnaviv/Kconfig | 2 ++ > > 1 file changed, 2 insertions(+) > > > > diff --git a/drivers/gpu/drm/etnaviv/Kconfig > > b/drivers/gpu/drm/etnaviv/Kconfig index 71cee4e9fefb..38b477b5fbf9 100644 > > --- a/drivers/gpu/drm/etnaviv/Kconfig > > +++ b/drivers/gpu/drm/etnaviv/Kconfig > > @@ -10,6 +10,8 @@ config DRM_ETNAVIV > > select IOMMU_API > > select IOMMU_SUPPORT > > select WANT_DEV_COREDUMP > > + select CMA if HAVE_DMA_CONTIGUOUS > > + select DMA_CMA if HAVE_DMA_CONTIGUOUS > > help > > DRM driver for Vivante GPUs. > IIRC, This at least half solves it. > Does the user of systems with > 2 GiB need to explicitly specify cma size for > it to work? No, we move the linear memory window to the location of the CMA area, which means as long as the user doesn't explicitly specify a CMA size > 2GB things will just work. Regards, Lucas
diff --git a/drivers/gpu/drm/etnaviv/Kconfig b/drivers/gpu/drm/etnaviv/Kconfig index 71cee4e9fefb..38b477b5fbf9 100644 --- a/drivers/gpu/drm/etnaviv/Kconfig +++ b/drivers/gpu/drm/etnaviv/Kconfig @@ -10,6 +10,8 @@ config DRM_ETNAVIV select IOMMU_API select IOMMU_SUPPORT select WANT_DEV_COREDUMP + select CMA if HAVE_DMA_CONTIGUOUS + select DMA_CMA if HAVE_DMA_CONTIGUOUS help DRM driver for Vivante GPUs.
While this is no build dependency, etnaviv will only work correctly on most systems if CMA and DMA_CMA are enabled. Select both options if available to avoid users ending up with a non-working GPU due to a lacking kernel config. Signed-off-by: Lucas Stach <l.stach@pengutronix.de> --- drivers/gpu/drm/etnaviv/Kconfig | 2 ++ 1 file changed, 2 insertions(+)