Drm: mgag200. Video adapter issue with 5.4.0-rc3 ; no graphics
John Donnelly
john.p.donnelly at oracle.com
Fri Nov 8 18:07:04 UTC 2019
> 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.
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