[PATCH] drm/exynos: Add check for IOMMU while passing physically continous memory flag

[Vikas Sajjan]

Hi Tomasz,


On 2 August 2013 04:50, Tomasz Figa <tomasz.figa at gmail.com> wrote:
>
> Hi Vikas,
>
> On Thursday 01 of August 2013 16:49:32 Vikas Sajjan wrote:
> > While trying to get boot-logo up on exynos5420 SMDK which has eDP panel
> > connected with resolution 2560x1600, following error occured even with
> > IOMMU enabled:
> > [0.880000] [drm:lowlevel_buffer_allocate] *ERROR* failed to allocate
> > buffer. [0.890000] [drm] Initialized exynos 1.0.0 20110530 on minor 0
> >
> > This patch fixes the issue by adding a check for IOMMU.
> >
> > Signed-off-by: Vikas Sajjan <vikas.sajjan at linaro.org>
> > Signed-off-by: Arun Kumar <arun.kk at samsung.com>
> > ---
> >  drivers/gpu/drm/exynos/exynos_drm_fbdev.c |    9 ++++++++-
> >  1 file changed, 8 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/gpu/drm/exynos/exynos_drm_fbdev.c
> > b/drivers/gpu/drm/exynos/exynos_drm_fbdev.c index 8e60bd6..2a86666
> > 100644
> > --- a/drivers/gpu/drm/exynos/exynos_drm_fbdev.c
> > +++ b/drivers/gpu/drm/exynos/exynos_drm_fbdev.c
> > @@ -16,6 +16,7 @@
> >  #include <drm/drm_crtc.h>
> >  #include <drm/drm_fb_helper.h>
> >  #include <drm/drm_crtc_helper.h>
> > +#include <drm/exynos_drm.h>
> >
> >  #include "exynos_drm_drv.h"
> >  #include "exynos_drm_fb.h"
> > @@ -143,6 +144,7 @@ static int exynos_drm_fbdev_create(struct
> > drm_fb_helper *helper, struct platform_device *pdev = dev->platformdev;
> >       unsigned long size;
> >       int ret;
> > +     unsigned int flag;
> >
> >       DRM_DEBUG_KMS("surface width(%d), height(%d) and bpp(%d\n",
> >                       sizes->surface_width, sizes->surface_height,
> > @@ -166,7 +168,12 @@ static int exynos_drm_fbdev_create(struct
> > drm_fb_helper *helper, size = mode_cmd.pitches[0] * mode_cmd.height;
> >
> >       /* 0 means to allocate physically continuous memory */
> > -     exynos_gem_obj = exynos_drm_gem_create(dev, 0, size);
> > +     if (!is_drm_iommu_supported(dev))
> > +             flag = 0;
> > +     else
> > +             flag = EXYNOS_BO_NONCONTIG;
>
> While noncontig memory might be used for devices that support IOMMU, there
> should be no problem with using contig memory for them, so this seems more
> like masking the original problem rather than tracking it down.
>
> Could you check why the allocation fails when requesting contiguous
> memory?
>

It is failing if i am giving bigger resolution like 2560x1600, but if
i try for 1280x780 resolution, it   works fine.
Looks like arm_dma_alloc() is NOT able to allocate bigger buffer of
size 2560 * 1600 * 4.
Hence i used flag = EXYNOS_BO_NONCONTIG;


>
> Best regards,
> Tomasz
>



-- 
Thanks and Regards
 Vikas Sajjan