Re: writing custom driver for VGA emulation ?

Christian König <ckoenig.leichtzumerken@xxxxxxxxx> · Tue, 18 Feb 2020 16:33:26 +0100



    Hi Yusuf,

      
      good to hear that you were able to solve your MMIO problems.

      
      And yes amdgpu has unfortunately some bugs on big endian systems.

      
      But as John noted when you solved the issues with the MMIO BARs
      you can also use the Vesa driver with the VGA emulation.

      
      Regards,

      Christian.

      
      Am 18.02.20 um 16:00 schrieb Yusuf Altıparmak:

    
              Hello Mr. Alex, Mr. Cönig and Mr.
                  Bridgman, 
              

              Mr. Cönig, we have talked about MMIO
                  problem before. You helped me a lot about that and now
                  driver is not giving any error about MMIO. That
                  problem was about bus configuration of my embedded
                  system. It does not proceed more than 4GB besides 0x0
                  adress is aligned for I/O and MMIO is allowed between
                  0xE0000000 and 0xffffffff. Fortunately, I now am able
                  to claim 256 MB and other 4 BARs adress between this
                  range. I can attach lspci -v output. 
              

              Mr. Bridgman, I am using U-boot as
                  bootloader and the system is 64 bit PowerPc e5500
                  core. This means big endian kernel. 
              

              Right now, the driver 'amdgpu' is
                  having error when 
              it tries to load smc firmware. I ve
                  been trying to solve this problem for months but I
                  haven't solve it yet. 
              

              Other firmwares seems loading without
                  any error. I was suspecting that endianness is causing
                  this problem but if it was shouldn't other firmwares
                  get fail before smc firmware gets loaded? 
              

              I tried all of the firmwares in
                  repository but result remained same. 
              

              Full dmesg:

              
              [    5.426009] [drm] amdgpu kernel
                modesetting enabled.                                   
                                                  

              [    5.430109] [drm] initializing kernel modesetting
              (POLARIS12 0x1002:0x6987 0x1787:0x2389 0x80).            
                           

              [    5.437591] [drm] register mmio base: 0x20200000      
                                                                       
                       
              [    5.440899] [drm] register mmio size: 262144          
                                                                       
                       
              [    5.443888] [drm] add ip block number 0
              <vi_common>                                        
                                           

              [    5.447465] [drm] add ip block number 1
              <gmc_v8_0>                                          
                                           

              [    5.450953] [drm] add ip block number 2
              <tonga_ih>                                          
                                           

              [    5.454442] [drm] add ip block number 3
              <powerplay>                                        
                                           

              [    5.458018] [drm] add ip block number 4 <dm>    
                                                                       
                             
              [    5.460979] [drm] add ip block number 5
              <gfx_v8_0>                                          
                                           

              [    5.464466] [drm] add ip block number 6
              <sdma_v3_0>                                        
                                           

              [    5.468042] [drm] add ip block number 7
              <uvd_v6_0>                                          
                                           

              [    5.471531] [drm] add ip block number 8
              <vce_v3_0>                                          
                                           

              [    5.475047] [drm] UVD is enabled in VM mode            
                                                                       
                     
              [    5.477928] [drm] UVD ENC is enabled in VM mode        
                                                                       
                     
              [    5.481154] [drm] VCE enabled in VM mode              
                                                                       
                       
              [    5.712355] ATOM BIOS: 113-ER16BFC-001                
                                                                       
                       
              [    5.714830] [drm] GPU posting now...                  
                                                                       
                       
              [    5.833704] [drm] vm size is 64 GB, 2 levels, block
              size is 10-bit, fragment size is 9-bit                    
                         

              [    5.840950] amdgpu 0001:01:00.0: BAR 2: releasing [mem
              0x220000000-0x2201fffff 64bit pref]                      
                       

              [    5.847930] amdgpu 0001:01:00.0: BAR 0: releasing [mem
              0x210000000-0x21fffffff 64bit pref]                      
                       

              [    5.855688] [drm:.amdgpu_device_resize_fb_bar [amdgpu]]
              *ERROR* Problem resizing BAR0 (-2).                      
                     

              [    5.855706] amdgpu 0001:01:00.0: BAR 0: assigned [mem
              0x230000000-0x23fffffff 64bit pref]                      
                       

              [    5.869663] amdgpu 0001:01:00.0: BAR 2: assigned [mem
              0x240000000-0x2401fffff 64bit pref]                      
                       

              [    5.876582] amdgpu 0001:01:00.0: VRAM: 4096M
              0x000000F400000000 - 0x000000F4FFFFFFFF (4096M used)      
                               

              [    5.884160] amdgpu 0001:01:00.0: GART: 256M
              0x0000000000000000 - 0x000000000FFFFFFF                  
                                 

              [    5.890519] [drm] Detected VRAM RAM=4096M, BAR=256M    
                                                                       
                     
              [    5.894093] [drm] RAM width 128bits GDDR5              
                                                                       
                     
              [    5.896941] [TTM] Zone  kernel: Available graphics
              memory: 4062380 kiB                                      
                           

              [    5.902177] [TTM] Zone   dma32: Available graphics
              memory: 2097152 kiB                                      
                           

              [    5.907402] [TTM] Initializing pool allocator          
                                                                       
                     
              [    5.910464] [TTM] Initializing DMA pool allocator      
                                                                       
                     
              [    5.919973] [drm] amdgpu: 4096M of VRAM memory ready  
                                                                       
                       
              [    5.923659] [drm] amdgpu: 4096M of GTT memory ready.  
                                                                       
                       
              [    5.927358] [drm] GART: num cpu pages 65536, num gpu
              pages 65536                                              
                         

              [    5.932957] [drm] PCIE GART of 256M enabled (table at
              0x000000F400000000).                                      
                       

              [    5.939122] [drm] Chained IB support enabled!          
                                                                       
                     
              [    5.948873] [drm] Found UVD firmware Version: 1.79
              Family ID: 16                                            
                           

              [    5.953647] [drm] UVD ENC is disabled                  
                                                                       
                     
              [    5.975818] [drm] Found VCE firmware Version: 52.4
              Binary ID: 3                                              
                         

              [    6.404774] amdgpu: [powerplay] Failed to send Message.
                                                                       
                     
              [    6.835902] amdgpu: [powerplay] SMU Firmware start
              failed!                                                  
                           

              [    6.840086] amdgpu: [powerplay] Failed to load SMU
              ucode.                                                    
                         

              [    6.844184] amdgpu: [powerplay] smc start failed      
                                                                       
                       
              [    6.847498] amdgpu: [powerplay] powerplay hw init
                failed                                              
                                 

              [    6.852281] [drm:.amdgpu_device_init [amdgpu]]
                *ERROR* hw_init of IP block <powerplay> failed -22  
                                   

              [    6.859883] amdgpu 0001:01:00.0:
                amdgpu_device_ip_init failed                    
                                                       

                [    6.864330] amdgpu 0001:01:00.0: Fatal error during
                GPU init                                        
                                     

                [    6.868689] [drm] amdgpu: finishing device.      
                                                                       
                           
              [    7.339427] pcieport 0001:00:00.0: AER: Corrected
                error received: 0001:00:00.0                            
                               

                [    7.345374] pcieport 0001:00:00.0: PCIe Bus Error:
                severity=Corrected, type=Data Link Layer, (Transmitter
                ID)            

                [    7.353993] pcieport 0001:00:00.0:   device
                [1957:0824] error status/mask=00001000/00002000        
                                     

                [    7.361047] pcieport 0001:00:00.0:    [12] Timeout  
                                                                   
                               
              [    7.706137] amdgpu: [powerplay]                        
                                                                       
                     
                              last message was failed ret is 0          
                                                                       
                     
              [    8.127667] amdgpu: [powerplay]                        
                                                                       
                     
                              failed to send message 261 ret is 0      
                                                                       
                       
              [    8.966331] amdgpu: [powerplay]                        
                                                                       
                     
                              last message was failed ret is 0          
                                                                       
                     
              [    9.320290] pcieport 0001:00:00.0: AER: Corrected error
              received: 0001:00:00.0                                    
                     

              [    9.326226] pcieport 0001:00:00.0: PCIe Bus Error:
              severity=Corrected, type=Data Link Layer, (Transmitter ID)
                         

              [    9.334845] pcieport 0001:00:00.0:   device [1957:0824]
              error status/mask=00001000/00002000                      
                     

              [    9.341899] pcieport 0001:00:00.0:    [12] Timeout    
                                                                       
                       
              [    9.387975] amdgpu: [powerplay]                        
                                                                       
                     
                              failed to send message 261 ret is 0      
                                                                       
                       
              [   10.226636] amdgpu: [powerplay]                        
                                                                       
                     
                              last message was failed ret is 0          
                                                                       
                     
              [   10.648275] amdgpu: [powerplay]                        
                                                                       
                     
                              failed to send message 261 ret is 0      
                                                                       
                       
              [   11.486932] amdgpu: [powerplay]                        
                                                                       
                     
                              last message was failed ret is 0          
                                                                       
                     
              [   11.908570] amdgpu: [powerplay]                        
                                                                       
                     
                              failed to send message 261 ret is 0      
                                                                       
                       
              [   12.747228] amdgpu: [powerplay]                        
                                                                       
                     
                              last message was failed ret is 0          
                                                                       
                     
              [   13.168866] amdgpu: [powerplay]                        
                                                                       
                     
                              failed to send message 261 ret is 0      
                                                                       
                       
              [   14.007523] amdgpu: [powerplay]                        
                                                                       
                     
                              last message was failed ret is 0          
                                                                       
                     
              [   14.429161] amdgpu: [powerplay]                        
                                                                       
                     
                              failed to send message 261 ret is 0      
                                                                       
                       
              [   15.267816] amdgpu: [powerplay]                        
                                                                       
                     
                              last message was failed ret is 0          
                                                                       
                     
              [   15.689456] amdgpu: [powerplay]                        
                                                                       
                     
                              failed to send message 261 ret is 0      
                                                                       
                       
              [   16.528114] amdgpu: [powerplay]                        
                                                                       
                     
                              last message was failed ret is 0          
                                                                       
                     
              [   16.949756] amdgpu: [powerplay]                        
                                                                       
                     
                              failed to send message 261 ret is 0      
                                                                       
                       
              [   17.788411] amdgpu: [powerplay]                        
                                                                       
                     
                              last message was failed ret is 0          
                                                                       
                     
              [   18.210051] amdgpu: [powerplay]                        
                                                                       
                     
                              failed to send message 261 ret is 0      
                                                                       
                       
              [   19.048710] amdgpu: [powerplay]                        
                                                                       
                     
                              last message was failed ret is 0          
                                                                       
                     
              [   19.470347] amdgpu: [powerplay]                        
                                                                       
                     
                              failed to send message 261 ret is 0      
                                                                       
                       
              [   19.786774] [TTM] Finalizing pool allocator            
                                                                       
                     
              [   19.789696] [TTM] Finalizing DMA pool allocator        
                                                                       
                     
              [   19.793004] [TTM] Zone  kernel: Used memory at exit: 0
              kiB                                                      
                       

              [   19.797209] [TTM] Zone   dma32: Used memory at exit: 0
              kiB                                                      
                       

              [   19.801410] [drm] amdgpu: ttm finalized                
                                                                     
                         
                [   19.804496] amdgpu: probe of 0001:01:00.0 failed with
                error -22 

            
          18 Şub 2020 Sal 17:43
            tarihinde Bridgman, John <John.Bridgman@xxxxxxx>
            şunu yazdı:

          
                [AMD Official Use Only - Internal Distribution Only]

              
                >And
                  we already checked, 256MB is unfortunately the minimum
                  you can resize the VRAM BAR on the E9171 to.

                
                Ahh,
                  OK... I didn't realize we had already looked into
                  that. I guess that approach isn't going to work.
                  

                Yusef,
                  guessing you are using a 32-bit CPU ? Is it possible
                  to talk to whoever does SBIOS for your platform to see
                  if you could maybe reduce address space allocated to
                  RAM and bump up the MMIO space ?

                
                  From:
                      Christian König <ckoenig.leichtzumerken@xxxxxxxxx>

                      Sent: February 18, 2020 9:19 AM

                      To: Bridgman, John <John.Bridgman@xxxxxxx>;
                      Alex Deucher <alexdeucher@xxxxxxxxx>;
                      Yusuf Altıparmak <yusufalti1997@xxxxxxxxx>

                      Cc: amd-gfx list <amd-gfx@xxxxxxxxxxxxxxxxxxxxx>

                      Subject: Re: writing custom driver for VGA
                      emulation ?
                     
                  
                    The problem Yusuf runs into is that his
                      platform has multiple PCIe root hubs, but only
                      512MB of MMIO address space. That is not enough to
                      fit all the BARs of an E9171 into.

                      
                      But without the BARs neither the VGA emulation nor
                      amdgpu not anything else will work correctly.

                      
                      And we already checked, 256MB is unfortunately the
                      minimum you can resize the VRAM BAR on the E9171
                      to.

                      
                      What could maybe work is to trick the upstream
                      bridge of the VGA device into not routing all the
                      addresses to the BARs and actually use only a
                      smaller portion of visible VRAM. But that would be
                      highly experimental and requires a rather big hack
                      into the PCI(e) subsystem in the Linux kernel.

                      
                      Regards,

                      Christian.

                      
                      Am 18.02.20 um 15:08 schrieb Bridgman, John:

                    
                        [AMD Official Use Only - Internal Distribution
                        Only]

                      
                        Does the VBIOS come up with something like
                          a splash screen, ie is VBIOS able to
                          initialize and drive the card ?

                        
                        If so then another option might be to use a
                          VESA driver rather than VGA. 

                        
                          From:
                              amd-gfx
                              
<amd-gfx-bounces@xxxxxxxxxxxxxxxxxxxxx> on behalf of Alex
                              Deucher 
                                <alexdeucher@xxxxxxxxx>

                              Sent: February 18, 2020 8:50 AM

                              To: Yusuf Altıparmak 
                                <yusufalti1997@xxxxxxxxx>

                              Cc: amd-gfx list 
                                <amd-gfx@xxxxxxxxxxxxxxxxxxxxx>

                              Subject: Re: writing custom driver
                              for VGA emulation ?
                             
                          
                                On Tue, Feb 18, 2020 at 2:56 AM
                                  Yusuf Altıparmak

                                  <yusufalti1997@xxxxxxxxx>
                                  wrote:

                                  >

                                  > Hello AMD team;

                                  >

                                  > I have E 9171 GPU and want to use
                                  it on a embedded system which has
                                  limited MMIO space on PCIe bus (MAX
                                  512 MB).

                                  >

                                  > I received feedbacks that I can
                                  only use VGA emulation with this
                                  memory space. I was unable to get
                                  'amdgpu' driver working with Xorg due
                                  to I had many errors(firmwares are not
                                  loading) in each step and tired of
                                  solving them one by one.

                                  >

                                  > I want to write a simple custom
                                  driver for this GPU with kernel
                                  version 4.19.

                                  > Is it possible to print some
                                  colors on screen with a custom driver
                                  over PCIe communication ? or writing
                                  some words on screen as VGA ?

                                  >

                                  > If answer is yes, then which code
                                  pieces (on amdgpu driver folder) or
                                  reference documentation should I use?
                                  I have Register Reference Guide.pdf.

                                  >

                                  > I will be appreciated for your
                                  guidance.

                                  
                                  That is not going to do what you want
                                  on your platform.  The VGA

                                  emulation requires that you set up the
                                  card first to enable it, which

                                  in turn requires MMIO access and thus
                                  you are back to square one.

                                  
                                  Alex

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