Ok, thanks! -----Original Message----- From: Christian König [mailto:deathsimple@xxxxxxxxxxx] Sent: Friday, July 21, 2017 10:12 PM To: Yu, Xiangliang <Xiangliang.Yu at amd.com>; amd-gfx at lists.freedesktop.org Subject: Re: [PATCH] drm/amdgpu: reduce the time of reading VBIOS Am 21.07.2017 um 04:52 schrieb Xiangliang.Yu: > From: Xiangliang Yu <Xiangliang.Yu at amd.com> > > Change ioremap mode from noncache to write combine and it will reduce > the read vbios time from 188ms to 8ms. Nice improvement, but I think you need to improve the commit message a bit. Changing the ioremap mode from noncache to write combine should actually not improve the read performance (reads are uncached in both modes). I think this patch makes a difference because VRAM is usually marked write combined and so ioremap needs to change that for no good reason and that in turn takes quite some time. I think you should write something like "Avoid changing the mapping mode of VRAM while reading the vbios from it, this reduce the time from....". > > Signed-off-by: Xiangliang Yu <Xiangliang.Yu at amd.com> > Signed-off-by: Xiangliang.Yu <Xiangliang.Yu at amd.com> You added the signed-off-by line twice, please fix this. With that fixed and the commit message improved a bit the patch is Reviewed-by: Christian König <christian.koenig at amd.com>. Regards, Christian. > --- > drivers/gpu/drm/amd/amdgpu/amdgpu_bios.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_bios.c > b/drivers/gpu/drm/amd/amdgpu/amdgpu_bios.c > index ea3a250..c21adf6 100644 > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_bios.c > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_bios.c > @@ -104,7 +104,7 @@ static bool igp_read_bios_from_vram(struct > amdgpu_device *adev) > > adev->bios = NULL; > vram_base = pci_resource_start(adev->pdev, 0); > - bios = ioremap(vram_base, size); > + bios = ioremap_wc(vram_base, size); > if (!bios) { > return false; > }
