Re: Why is mgag200 not used over matroxfb?

[Paul Menzel <pmenzel@molgen.mpg.de>]

Dear Thomas,


I have to correct myself.


Am 16.12.22 um 14:16 schrieb Paul Menzel:

> Am 16.12.22 um 13:27 schrieb Thomas Zimmermann:
> 
>> Am 15.12.22 um 17:39 schrieb Paul Menzel:
> 
> […]
> 
>>> Between Linux 5.10.103 and 5.10.110/5.15.77, matrixfb fails to load.
>>
>> Off-topic, but related. matroxfb is obsolete and there's a maintained 
>> DRM replacement (mgag200) for this hardware.
> 
> I also remembered something like this in the back of my head. Though I 
> thought about using simpledrm (`DRM_SIMPLEDRM`), we do not build though.
> 
>> Is there anything missing from mgag200 that prevents you from switching?
> No, it looks like the matroxfb modules take precedence over the mgag200 
> module:
> 
>      $ grep -e FB_MATROX -e MGAG /boot/config-5.15.77.mx64.440
>      CONFIG_DRM_MGAG200=m
>      CONFIG_FB_MATROX=m
>      CONFIG_FB_MATROX_MILLENIUM=y
>      CONFIG_FB_MATROX_MYSTIQUE=y
>      CONFIG_FB_MATROX_G=y
>      CONFIG_FB_MATROX_I2C=m
>      # CONFIG_FB_MATROX_MAVEN is not set
> 
>      $ lsmod | grep matrox
>      matroxfb_base          28672  0
>      matroxfb_g450          16384  1 matroxfb_base
>      matroxfb_Ti3026        16384  1 matroxfb_base
>      matroxfb_accel         16384  1 matroxfb_base
>      matroxfb_DAC1064       20480  1 matroxfb_base
>      g450_pll               16384  2 matroxfb_g450,matroxfb_DAC1064
>      matroxfb_misc          20480  5 g450_pll,matroxfb_Ti3026,matroxfb_base,matroxfb_g450,matroxfb_DAC1064

The search string was incorrect. The module mgag200, is loaded:

     $ lsmod | grep mgag200
     mgag200                36864  0
     drm_kms_helper        241664  3 mgag200
     drm                   524288  3 drm_kms_helper,mgag200
     i2c_algo_bit           16384  1 mgag200

and it is used according to `lspci`:

     $ lspci -nn -k -s 09:03.
     09:03.0 VGA compatible controller [0300]: Matrox Electronics 
Systems Ltd. MGA G200eW WPCM450 [102b:0532] (rev 0a)
         DeviceName: Embedded Video
         Subsystem: Dell MGA G200eW WPCM450 [1028:02d3]
         Kernel driver in use: mgag200
         Kernel modules: matroxfb_base, mgag200

So, it was only a cosmetic issue.


Kind regards,

Paul