Drm: mgag200. Video adapter issue with 5.4.0-rc3 ; no graphics

John Donnelly John.P.Donnelly at Oracle.com
Mon Nov 11 17:40:02 UTC 2019


On 11/11/19 9:57 AM, Thomas Zimmermann wrote:
> Hi John
> 
> Am 08.11.19 um 19:07 schrieb John Donnelly:
>>
>>
>>> On Nov 8, 2019, at 9:06 AM, Thomas Zimmermann <tzimmermann at suse.de> wrote:
>>>
>>> Hi
>>>
>>> Am 08.11.19 um 13:55 schrieb John Donnelly:
>>>>
>>>>
>>>>> On Nov 8, 2019, at 1:46 AM, Thomas Zimmermann <tzimmermann at suse.de> wrote:
>>>>>
>>>>> Hi John
>>>>>
>>>>> Am 07.11.19 um 23:14 schrieb John Donnelly:
>>>>>>
>>>>>>
>>>>>>> On Nov 7, 2019, at 10:13 AM, John Donnelly <john.p.donnelly at oracle.com> wrote:
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>> On Nov 7, 2019, at 7:42 AM, Thomas Zimmermann <tzimmermann at suse.de> wrote:
>>>>>>>>
>>>>>>>> Hi John
>>>>>>>>
>>>>>>>> Am 07.11.19 um 14:12 schrieb John Donnelly:
>>>>>>>>> Hi  Thomas ;  Thank you for reaching out.
>>>>>>>>>
>>>>>>>>> See inline:
>>>>>>>>>
>>>>>>>>>> On Nov 7, 2019, at 1:54 AM, Thomas Zimmermann <tzimmermann at suse.de> wrote:
>>>>>>>>>>
>>>>>>>>>> Hi John,
>>>>>>>>>>
>>>>>>>>>> apparently the vgaarb was not the problem.
>>>>>>>>>>
>>>>>>>>>> Am 07.11.19 um 03:29 schrieb John Donnelly:
>>>>>>>>>>> Hi,
>>>>>>>>>>>
>>>>>>>>>>> I am investigating an issue where we lose video activity when the display is switched from from “text mode” to “graphic mode”
>>>>>>>>>>> on a number of  servers using this driver.    Specifically  starting the GNOME desktop.
>>>>>>>>>>
>>>>>>>>>> When you say "text mode", do you mean VGA text mode or the graphical
>>>>>>>>>> console that emulates text mode?
>>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> I call “text mode” the 24x80  ascii mode ;  - NOT GRAPHICS .       Ie : run-level 3;  So I  guess your term for it is VGA.
>>>>>>>>
>>>>>>>> Yes.
>>>>>>>>
>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>> When you enable graphics mode, does it set the correct resolution? A lot
>>>>>>>>>> of work went into memory management recently. I could imagine that the
>>>>>>>>>> driver sets the correct resolution, but then fails to display the
>>>>>>>>>> correct framebuffer.
>>>>>>>>>
>>>>>>>>> There is no display at all ;  so there is no resolution  to mention.
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> If possible, could you try to update to the latest drm-tip and attach
>>>>>>>>>> the output of
>>>>>>>>>>
>>>>>>>>>> /sys/kernel/debug/dri/0/vram-mm
>>>>>>>>>
>>>>>>>>> I don’t see that file ;   Is there something else I need to do ?
>>>>>>>>
>>>>>>>> That file is fairly new and maybe it's not in the mainline kernel yet.
>>>>>>>> See below for how to get it.
>>>>>>>
>>>>>>> I  built your “tip” ;  Still no graphics displayed .
>>>>>>>
>>>>>>>
>>>>>>> mount -t debugfs none /sys/kernel
>>>>>>>
>>>>>>> cat /proc/cmdline
>>>>>>> BOOT_IMAGE=(hd0,msdos1)/vmlinuz-5.4.0-rc6.drm.+ root=/dev/mapper/ol_ca--dev55-root ro crashkernel=auto resume=/dev/mapper/ol_ca--dev55-swap rd.lvm.lv=ol_ca-dev55/root rd.lvm.lv=ol_ca-dev55/swap console=ttyS0,9600,8,n,1 drm.debug=0xff
>>>>>>>
>>>>>>>
>>>>>>> cat  /sys/kernel/dri/0/vram-mm
>>>>>>>
>>>>>>> In VGA mode :
>>>>>>>
>>>>>>>
>>>>>>> cat  /sys/kernel/dri/0/vram-mm
>>>>>>> 0x0000000000000000-0x0000000000000300: 768: used
>>>>>>> 0x0000000000000300-0x0000000000000600: 768: used
>>>>>>> 0x0000000000000600-0x00000000000007ee: 494: free
>>>>>>> 0x00000000000007ee-0x00000000000007ef: 1: used
>>>>>>> 0x00000000000007ef-0x00000000000007f0: 1: used
>>>>>>>
>>>>>>>
>>>>>>> In GRAPHICS mode ( if it matters )
>>>>>>>
>>>>>>>
>>>>>>> cat  /sys/kernel/dri/0/vram-mm
>>>>>>> 0x0000000000000000-0x0000000000000300: 768: used
>>>>>>> 0x0000000000000300-0x0000000000000600: 768: used
>>>>>>> 0x0000000000000600-0x00000000000007ee: 494: free
>>>>>>> 0x00000000000007ee-0x00000000000007ef: 1: used
>>>>>>> 0x00000000000007ef-0x00000000000007f0: 1: used
>>>>>>> total: 2032, used 1538 free 494
>>>>>>>
>>>>>
>>>>> This is interesting. In the graphics mode, you see two buffers of 768
>>>>> pages each. That's the main framebuffers as used by X (it's double
>>>>> buffered). Then there's a free area and finally two pages for cursor
>>>>> images (also double buffered). That looks as expected.
>>>>>
>>>>> The thing is that in text mode, the areas are allocated. But the driver
>>>>> shouldn't be active, so the file shouldn't exist or only show a single
>>>>> free area.
>>>>>
>>>>
>>>>       If you want me to double check this I will .    I have GNOME installed , but the machine boots to runlevel  3, then I start the desktop using init 5  I am pretty sure I took that output when the machine was in graphic’s mode   at runlevel 5 .
>>>>
>>>>
>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>>
>>>>>>>>> I’ve attached : var/lib/gdm/.local/share/xorg/Xorg.0.log. ;   instead ;
>>>>>>>>
>>>>>>>> Good! Looking through that log file, the card is found at line 79 and
>>>>>>>> the generic X modesetting driver initializes below. That works as expected.
>>>>>>>>
>>>>>>>> I notices that several operations are not permitted (lines 78 and 87). I
>>>>>>>> guess you're starting X from a regular user account? IIRC special
>>>>>>>> permission is required to acquire control of the display. What happens
>>>>>>>> if you start X as root user?
>>>>>>>
>>>>>>>
>>>>>>>   I am starting GNOME  as  root by doing  “init 5” from either the console  session or from ssh .
>>>>>>>
>>>>>>> The default runlevel is 3  on boot .
>>>>>>>
>>>>>>> On failing session  running  your 5.4.0.rc6.
>>>>>>>
>>>>>>> 78 [   237.712] xf86EnableIOPorts: failed to set IOPL for I/O (Operation not permitted)
>>>>>>>
>>>>>>> 87 [   237.712] (EE) open /dev/fb0: Permission denied
>>>>>>>
>>>>>>> Booting 4.18 kernel yields the same error results in: /var/lib/gdm/.local/share/xorg/Xorg.0.log
>>>>>>>
>>>>>>> 78 [   101.334] xf86EnableIOPorts: failed to set IOPL for I/O (Operation not permitted)
>>>>>>>
>>>>>>> 87 [   101.334] (EE) open /dev/fb0: Permission denied
>>>>>>>
>>>>>>>
>>>>>>> What is strange the X logs  ( bad and Ok ) files essentially appear as if GNOME started !
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> <Xorg.0.log.bad><Xorg.0.log.Ok>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> Here is my cmdline  -  I just tested 5.3.0 and it fails too  ( my last test was 5.3.8 and it failed also ) .
>>>>>>>>>
>>>>>>>>> # cat /proc/cmdline
>>>>>>>>> BOOT_IMAGE=(hd0,msdos1)/vmlinuz-5.3.0+ root=/dev/mapper/ol_ca--dev55-root ro crashkernel=auto resume=/dev/mapper/ol_ca--dev55-swap rd.lvm.lv=ol_ca-dev55/root rd.lvm.lv=ol_ca-dev55/swap console=ttyS0,9600,8,n,1 drm.debug=0xff
>>>>>>>>>
>>>>>>>>> When you say “tip”. - Are you referring to a specific kernel  ?  I can build a  5.4.0.rc6  ;   The problem appears to have been introduced around 5.3 time frame.
>>>>>>>>
>>>>>>>> The latest and greatest DRM code is in the drm-tip branch at
>>>>>>>>
>>>>>>>> git://anongit.freedesktop.org/drm/drm-tip
>>>>>>>>
>>>>>>>> If you build this version you should find
>>>>>>>>
>>>>>>>> /sys/kernel/debug/dri/0/vram-mm
>>>>>>>>
>>>>>>>> on the device. You have to build with debugfs enabled and
>>>>>>>> maybe have to mount debugfs at /sys/kernel/debug.
>>>>>>>>
>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> before and after switching to graphics mode. The file lists the
>>>>>>>>>> allocated regions of the VRAM.
>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> This adapter is  Server Engines  Integrated Remote Video Acceleration Subsystem (RVAS)  and is used as remote console in iLO/DRAC environments.
>>>>>>>>>>>
>>>>>>>>>>> I don’t see any specific errors in the gdm logs or message file other than this:
>>>>>>>>>>
>>>>>>>>>> You can boot with drm.debug=0xff on the kernel command line to enable
>>>>>>>>>> more warnings.
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> Could you please attach the output of lspci -v for the VGA adapter?
>>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> Here is the output from the current machine; The previous addresses were from another model using the same SE device:
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> Nov  7 04:42:50 ca-dev55 kernel: mgag200 0000:3d:00.0: remove_conflicting_pci_framebuffers: bar 0: 0xc5000000 -> 0xc5ffffff
>>>>>>>>> Nov  7 04:42:50 ca-dev55 kernel: mgag200 0000:3d:00.0: remove_conflicting_pci_framebuffers: bar 1: 0xc6810000 -> 0xc6813fff
>>>>>>>>> Nov  7 04:42:50 ca-dev55 kernel: mgag200 0000:3d:00.0: remove_conflicting_pci_framebuffers: bar 2: 0xc6000000 -> 0xc67fffff
>>>>>>>>> Nov  7 04:42:50 ca-dev55 kernel: mgag200 0000:3d:00.0: vgaarb: deactivate vga console
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> lspci -s 3d:00.0 -vvv -k
>>>>>>>>> 3d:00.0 VGA compatible controller: Matrox Electronics Systems Ltd. MGA G200e [Pilot] ServerEngines (SEP1) (rev 05) (prog-if 00 [VGA controller])
>>>>>>>>> 	Subsystem: Oracle/SUN Device 4852
>>>>>>>>> 	Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr+ Stepping- SERR+ FastB2B- DisINTx-
>>>>>>>>> 	Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-
>>>>>>>>> 	Latency: 0, Cache Line Size: 64 bytes
>>>>>>>>> 	Interrupt: pin A routed to IRQ 16
>>>>>>>>> 	NUMA node: 0
>>>>>>>>> 	Region 0: Memory at c5000000 (32-bit, non-prefetchable) [size=16M]
>>>>>>>>> 	Region 1: Memory at c6810000 (32-bit, non-prefetchable) [size=16K]
>>>>>>>>> 	Region 2: Memory at c6000000 (32-bit, non-prefetchable) [size=8M]
>>>>>>>>> 	Expansion ROM at 000c0000 [disabled] [size=128K]
>>>>>>>>> 	Capabilities: [dc] Power Management version 2
>>>>>>>>> 		Flags: PMEClk- DSI+ D1- D2- AuxCurrent=0mA PME(D0-,D1-,D2-,D3hot-,D3cold-)
>>>>>>>>> 		Status: D0 NoSoftRst- PME-Enable- DSel=0 DScale=0 PME-
>>>>>>>>> 	Capabilities: [e4] Express (v1) Legacy Endpoint, MSI 00
>>>>>>>>> 		DevCap:	MaxPayload 256 bytes, PhantFunc 0, Latency L0s <64ns, L1 <1us
>>>>>>>>> 			ExtTag- AttnBtn- AttnInd- PwrInd- RBE- FLReset-
>>>>>>>>> 		DevCtl:	Report errors: Correctable+ Non-Fatal+ Fatal+ Unsupported-
>>>>>>>>> 			RlxdOrd- ExtTag- PhantFunc- AuxPwr- NoSnoop-
>>>>>>>>> 			MaxPayload 128 bytes, MaxReadReq 128 bytes
>>>>>>>>> 		DevSta:	CorrErr+ UncorrErr- FatalErr- UnsuppReq+ AuxPwr- TransPend-
>>>>>>>>> 		LnkCap:	Port #0, Speed 2.5GT/s, Width x1, ASPM L0s, Exit Latency L0s <64ns
>>>>>>>>> 			ClockPM- Surprise- LLActRep- BwNot- ASPMOptComp-
>>>>>>>>> 		LnkCtl:	ASPM Disabled; RCB 64 bytes Disabled- CommClk+
>>>>>>>>> 			ExtSynch- ClockPM- AutWidDis- BWInt- AutBWInt-
>>>>>>>>> 		LnkSta:	Speed 2.5GT/s, Width x1, TrErr- Train- SlotClk+ DLActive- BWMgmt- ABWMgmt-
>>>>>>>>> 	Capabilities: [54] MSI: Enable- Count=1/1 Maskable- 64bit-
>>>>>>>>> 		Address: 00000000  Data: 0000
>>>>>>>>> 	Kernel driver in use: mgag200
>>>>>>>>> 	Kernel modules: mgag200
>>>>>>>>
>>>>>>>> Looks all normal.
>>>>>>>>
>>>>>>>> Best regards
>>>>>>>> Thomas
>>>>>>>>
>>>>>>
>>>>>> ==============  Snip  ===========
>>>>>>
>>>>>>
>>>>>> Hi Thomas
>>>>>> ,
>>>>>> I hopefully narrowed down the breakage between these up-stream commits,  which is v5.2 and 5.3.0-rc1:
>>>>>>
>>>>>>
>>>>>> between :  0ecfebd2b524 2019-07-07 | Linux 5.2      to :   5f9e832c1370 2019-07-21 | Linus 5.3-rc1
>>>>>>
>>>>>>
>>>>>> I started to bisect this range on by date, by day ,  based on the changes done in :
>>>>>>
>>>>>> drivers/gpu/drm/
>>>>>>
>>>>>> fec88ab0af97 2019-07-14 | Merge tag 'for-linus-hmm' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma  ;  works
>>>>>>
>>>>>> Hopefully something in drivers/gpu/drm/ between the date range of 2019-07-14 to 2019-07-21 will surface tomorrow.
>>>>>
>>>>> Great, thanks for bisecting.
>>>>>
>>>>> Could you attach your kernel config file? I'd like to compare with my
>>>>> config and try to reproduce the issue.
>>>>>
>>>>> Best regards
>>>>> Thomas
>>>>
>>>>   Hi.
>>>>
>>>>   Here are config files generated after a “ make oldconfig “     that started with an original .config file from a master file  we use for 5.4.0.-rc4. :
>>>>
>>>>      config.5.2.21 -  work with that flavor
>>>>     config.5.3.   fails with 5.3 and later.
>>>>
>>>>   Do you have access to mgag200 style adapter ?
>>>
>>> I do.
>>>
>>> I think I've been able to reproduce the issue. Buffers seem to remain in
>>> video ram after they have been pinned there. I'll investigate next week.
>>> I hope your bisecting session can point to the cause.
>>>
>>> Best regards
>>> Thomas
>>
>> Hi Thomas,
>>
>>
>>   Wonderful!
>>
>>   I think I have narrowed down the merge to this build which is : vmlinuz-5.2.0-rc5+ :
>>
>>
>> be8454afc50f 2019-07-15 | Merge tag 'drm-next-2019-07-16' of git://anongit.freedesktop.org/drm/drm
>>
>>    Specifically this merge included these two changes :
>>
>>    94dc57b10399 2019-06-13 | drm/mgag200: Rewrite cursor handling
>>    f4ce5af71bc2 2019-06-13 | drm/mgag200: Pin framebuffer BO during dirty update
>>
>>
>> I  tried reverting them and the resultant driver  doesn’t build afterwards due to drm calls.
>>
>> If I build a kernel from :
>>
>> fec88ab0af97 2019-07-14 | Merge tag 'for-linus-hmm' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma
>>
>> That is posted  day prior to  be8454afc50f - the GNOME desktop works.
> 
> I thought I could reproduce the problem, but I'm not so sure now.
> 
> Please bisect the range between the two merges as described by Daniel to
> find the broken commit. Doing
> 
>    git bisect start
>    git bisect bad be8454afc50f
>    git bisect good fec88ab0af97
> 
> should start the session.
> 
Hi,

I am OoO today . I will start this exercise tomorrow.




-- 
Thank You,
John


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