Re: [PATCH] drm/amdgpu: Fixup bad vram size on gmc v6 and v7

From: Qiang Ma
Date: Tue Apr 23 2024 - 22:32:19 EST

On Mon, 22 Apr 2024 16:47:36 +0200
Christian König <christian.koenig@xxxxxxx> wrote:

> Am 22.04.24 um 16:40 schrieb Alex Deucher:
> > On Mon, Apr 22, 2024 at 9:00 AM Christian König
> > <christian.koenig@xxxxxxx> wrote:
> >> Am 22.04.24 um 14:33 schrieb Qiang Ma:
> >>> On Mon, 22 Apr 2024 11:40:26 +0200
> >>> Christian König <christian.koenig@xxxxxxx> wrote:
> >>>
> >>>> Am 22.04.24 um 07:26 schrieb Qiang Ma:
> >>>>> Some boards(like Oland PRO: 0x1002:0x6613) seem to have
> >>>>> garbage in the upper 16 bits of the vram size register,
> >>>>> kern log as follows:
> >>>>>
> >>>>> [ 6.000000] [drm] Detected VRAM RAM=2256537600M, BAR=256M
> >>>>> [ 6.007812] [drm] RAM width 64bits GDDR5
> >>>>> [ 6.031250] [drm] amdgpu: 2256537600M of VRAM memory ready
> >>>>>
> >>>>> This is obviously not true, check for this and clamp the size
> >>>>> properly. Fixes boards reporting bogus amounts of vram,
> >>>>> kern log as follows:
> >>>>>
> >>>>> [ 2.789062] [drm] Probable bad vram size: 0x86800800
> >>>>> [ 2.789062] [drm] Detected VRAM RAM=2048M, BAR=256M
> >>>>> [ 2.789062] [drm] RAM width 64bits GDDR5
> >>>>> [ 2.789062] [drm] amdgpu: 2048M of VRAM memory ready
> >>>> Well we had patches like this one here before and so far we
> >>>> always rejected them.
> >>>>
> >>>> When the mmCONFIG_MEMSIZE register isn't properly initialized
> >>>> then there is something wrong with your hardware.
> >>>>
> >>>> Working around that in the software driver is not going to fly.
> >>>>
> >>>> Regards,
> >>>> Christian.
> >>>>
> >>> Hi Christian:
> >>> I see that two patches for this issue have been merged, and the
> >>> patches are as follows:
> >>>
> >>> 11544d77e397 drm/amdgpu: fixup bad vram size on gmc v8
> >>> 0ca223b029a2 drm/radeon: fixup bad vram size on SI
> >> Mhm, I remember that we discussed reverting those but it looks
> >> like that never happened. I need to ask around internally.
> >>
> >> Question is do you see any other problems with the board? E.g.
> >> incorrect connector or harvesting configuration?
> > I'll need to dig up the past discussion again, but IIRC, the issue
> > was only seen on some non-x86 platforms. Maybe something specific
> > to MMIO on those?
>
> I honestly doesn't remember it either, but in general it's the job of
> the VBIOS to init this register.
>
> So if we see the upper bits mangled the VBIOS hasn't done that
> correctly and it's quite likely that this is only the tip of the
> iceberg of problems.
>

Yes, this problem was found on the mips notebook. Check log vbios
signature incorrect, I don't know if it has any influence.
After add patch, drm logs are as follows:

[ 2.554687] [drm] amdgpu kernel modesetting enabled.
[ 2.558593] [drm] initializing kernel modesetting (OLAND
0x1002:0x6613 0x1028:0x1002 0x00). [ 2.558593] [drm] register mmio
base: 0x45400000 [ 2.558593] [drm] register mmio size: 262144
[ 2.558593] [drm] add ip block number 0 <si_common>
[ 2.558593] [drm] add ip block number 1 <gmc_v6_0>
[ 2.558593] [drm] add ip block number 2 <si_ih>
[ 2.558593] [drm] add ip block number 3 <si_dpm>
[ 2.558593] [drm] add ip block number 4 <dce_v6_0>
[ 2.558593] [drm] add ip block number 5 <gfx_v6_0>
[ 2.558593] [drm] add ip block number 6 <si_dma>
[ 2.578125] [drm] BIOS signature incorrect 0 0
[ 2.746093] [drm] vm size is 64 GB, 2 levels, block size is 10-bit,
fragment size is 9-bit [ 2.746093] [drm] Probable bad vram size:
0x86800800 [ 2.746093] [drm] Detected VRAM RAM=2048M, BAR=256M
[ 2.746093] [drm] RAM width 64bits GDDR5
[ 2.750000] [drm] amdgpu: 2048M of VRAM memory ready
[ 2.750000] [drm] amdgpu: 3072M of GTT memory ready.
[ 2.750000] [drm] GART: num cpu pages 65536, num gpu pages 262144
[ 2.750000] [drm] Supports vblank timestamp caching Rev 2
(21.10.2013). [ 2.750000] [drm] Driver supports precise vblank
timestamp query. [ 2.750000] [drm] Internal thermal controller with
fan control [ 2.750000] [drm] amdgpu: dpm initialized
[ 2.750000] [drm] amdgpu atom DIG backlight initialized
[ 2.750000] [drm] AMDGPU Display Connectors
[ 2.750000] [drm] Connector 0:
[ 2.750000] [drm] DP-1
[ 2.750000] [drm] HPD2
[ 2.750000] [drm] DDC: 0x1950 0x1950 0x1951 0x1951 0x1952 0x1952
0x1953 0x1953 [ 2.750000] [drm] Encoders:
[ 2.750000] [drm] LCD1: INTERNAL_UNIPHY
[ 2.750000] [drm] Connector 1:
[ 2.750000] [drm] HDMI-A-1
[ 2.750000] [drm] HPD1
[ 2.750000] [drm] DDC: 0x194c 0x194c 0x194d 0x194d 0x194e 0x194e
0x194f 0x194f [ 2.750000] [drm] Encoders:
[ 2.750000] [drm] DFP1: INTERNAL_UNIPHY
[ 2.753906] [drm] PCIE gen 2 link speeds already enabled
[ 3.507812] [drm] fb mappable at 0x503E4000
[ 3.507812] [drm] vram apper at 0x50000000
[ 3.507812] [drm] size 8306688
[ 3.507812] [drm] fb depth is 24
[ 3.507812] [drm] pitch is 7680
[ 4.632812] amdgpu 0000:05:00.0: fb0: amdgpudrmfb frame buffer device
[ 5.023437] [drm] Initialized amdgpu 3.27.0 20150101 for
0000:05:00.0 on minor 0


Qiang Ma

> Christian.
>
> >
> > Alex
> >
> >
> >> Regards,
> >> Christian.
> >>
> >>> Qiang Ma
> >>>
> >>>>> Signed-off-by: Qiang Ma <maqianga@xxxxxxxxxxxxx>
> >>>>> ---
> >>>>> drivers/gpu/drm/amd/amdgpu/gmc_v6_0.c | 11 +++++++++--
> >>>>> drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c | 13 ++++++++++---
> >>>>> 2 files changed, 19 insertions(+), 5 deletions(-)
> >>>>>
> >>>>> diff --git a/drivers/gpu/drm/amd/amdgpu/gmc_v6_0.c
> >>>>> b/drivers/gpu/drm/amd/amdgpu/gmc_v6_0.c index
> >>>>> 23b478639921..3703695f7789 100644 ---
> >>>>> a/drivers/gpu/drm/amd/amdgpu/gmc_v6_0.c +++
> >>>>> b/drivers/gpu/drm/amd/amdgpu/gmc_v6_0.c @@ -309,8 +309,15 @@
> >>>>> static int gmc_v6_0_mc_init(struct amdgpu_device *adev) }
> >>>>> adev->gmc.vram_width = numchan * chansize;
> >>>>> /* size in MB on si */
> >>>>> - adev->gmc.mc_vram_size = RREG32(mmCONFIG_MEMSIZE) *
> >>>>> 1024ULL * 1024ULL;
> >>>>> - adev->gmc.real_vram_size = RREG32(mmCONFIG_MEMSIZE) *
> >>>>> 1024ULL * 1024ULL;
> >>>>> + tmp = RREG32(mmCONFIG_MEMSIZE);
> >>>>> + /* some boards may have garbage in the upper 16 bits */
> >>>>> + if (tmp & 0xffff0000) {
> >>>>> + DRM_INFO("Probable bad vram size: 0x%08x\n", tmp);
> >>>>> + if (tmp & 0xffff)
> >>>>> + tmp &= 0xffff;
> >>>>> + }
> >>>>> + adev->gmc.mc_vram_size = tmp * 1024ULL * 1024ULL;
> >>>>> + adev->gmc.real_vram_size = adev->gmc.mc_vram_size;
> >>>>>
> >>>>> if (!(adev->flags & AMD_IS_APU)) {
> >>>>> r = amdgpu_device_resize_fb_bar(adev);
> >>>>> diff --git a/drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c
> >>>>> b/drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c index
> >>>>> 3da7b6a2b00d..1df1fc578ff6 100644 ---
> >>>>> a/drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c +++
> >>>>> b/drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c @@ -316,10 +316,10 @@
> >>>>> static void gmc_v7_0_mc_program(struct amdgpu_device *adev)
> >>>>> static int gmc_v7_0_mc_init(struct amdgpu_device *adev) {
> >>>>> int r;
> >>>>> + u32 tmp;
> >>>>>
> >>>>> adev->gmc.vram_width =
> >>>>> amdgpu_atombios_get_vram_width(adev); if
> >>>>> (!adev->gmc.vram_width) {
> >>>>> - u32 tmp;
> >>>>> int chansize, numchan;
> >>>>>
> >>>>> /* Get VRAM informations */
> >>>>> @@ -363,8 +363,15 @@ static int gmc_v7_0_mc_init(struct
> >>>>> amdgpu_device *adev) adev->gmc.vram_width = numchan * chansize;
> >>>>> }
> >>>>> /* size in MB on si */
> >>>>> - adev->gmc.mc_vram_size = RREG32(mmCONFIG_MEMSIZE) *
> >>>>> 1024ULL * 1024ULL;
> >>>>> - adev->gmc.real_vram_size = RREG32(mmCONFIG_MEMSIZE) *
> >>>>> 1024ULL * 1024ULL;
> >>>>> + tmp = RREG32(mmCONFIG_MEMSIZE);
> >>>>> + /* some boards may have garbage in the upper 16 bits */
> >>>>> + if (tmp & 0xffff0000) {
> >>>>> + DRM_INFO("Probable bad vram size: 0x%08x\n", tmp);
> >>>>> + if (tmp & 0xffff)
> >>>>> + tmp &= 0xffff;
> >>>>> + }
> >>>>> + adev->gmc.mc_vram_size = tmp * 1024ULL * 1024ULL;
> >>>>> + adev->gmc.real_vram_size = adev->gmc.mc_vram_size;
> >>>>>
> >>>>> if (!(adev->flags & AMD_IS_APU)) {
> >>>>> r = amdgpu_device_resize_fb_bar(adev);
>
>