Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]
Groups > linux.debian.kernel > #62382 > unrolled thread
| Started by | Priit Laes <plaes@plaes.org> |
|---|---|
| First post | 2018-10-17 08:40 +0200 |
| Last post | 2018-10-17 13:20 +0200 |
| Articles | 2 — 2 participants |
Back to article view | Back to linux.debian.kernel
Bug#911211: Increase default CMA size for armhf kernels Priit Laes <plaes@plaes.org> - 2018-10-17 08:40 +0200
Bug#911211: Increase default CMA size for armhf kernels Ben Hutchings <ben@decadent.org.uk> - 2018-10-17 13:20 +0200
| From | Priit Laes <plaes@plaes.org> |
|---|---|
| Date | 2018-10-17 08:40 +0200 |
| Subject | Bug#911211: Increase default CMA size for armhf kernels |
| Message-ID | <wJNER-5Oz-3@gated-at.bofh.it> |
Package: linux-image-armmp-lpae Version: 4.18+98~bpo9+1 Debian Stretch Currently, the default CMA size for armhf kernels is set to 16M. CMA allocator is used by display engine for storing framebuffer data. At least on sunxi platform (specifically OLinuxino-Lime2-eMMC device) it causes issues with larger displays (namely 1920x1080), because Xorg fails to start with following cryptic message: [snip] [ 855.117] (II) UnloadModule: "fbdev" [ 855.117] (II) Unloading fbdev [ 855.117] (II) UnloadSubModule: "fbdevhw" [ 855.117] (II) Unloading fbdevhw [ 855.118] (==) Depth 24 pixmap format is 32 bpp [ 855.118] (EE) Fatal server error: [ 855.118] (EE) AddScreen/ScreenInit failed for driver 0 [ 855.118] (EE) [ 855.119] (EE) [/snip] Increasing CMA size to 24MB (it seems that it can be increased only by 8MB steps) would be fine, because CMA memory utilization with 1920x1080 display is following: $ cat /proc/meminfo |grep Cma CmaTotal: 24576 kB CmaFree: 7932 kB
[toc] | [next] | [standalone]
| From | Ben Hutchings <ben@decadent.org.uk> |
|---|---|
| Date | 2018-10-17 13:20 +0200 |
| Message-ID | <wJS1P-8uN-1@gated-at.bofh.it> |
| In reply to | #62382 |
[Multipart message — attachments visible in raw view] — view raw
Control: clone -1 -2
Control: reassign -1 src:linux
Control: reassign -2 xserver-xorg-video-fbdev
Control: retitle -2 xserver-xorg-video-fbdev: No clear error message for init failure
On Wed, 2018-10-17 at 06:27 +0000, Priit Laes wrote:
> Package: linux-image-armmp-lpae
> Version: 4.18+98~bpo9+1
>
> Debian Stretch
>
> Currently, the default CMA size for armhf kernels is set to 16M.
> CMA allocator is used by display engine for storing framebuffer data.
>
> At least on sunxi platform (specifically OLinuxino-Lime2-eMMC device)
> it causes issues with larger displays (namely 1920x1080), because Xorg
> fails to start with following cryptic message:
[...]
The need for CMA is highly dependent on the hardware and applications
used. So I don't think we can set a default which will please
everyone. You can always override the built-in default size using the
cma parameter on the kernel command line.
That said, it seems reasonable to raise the default - when it is larger
than needed, the pages not allocated to the drivers that need it can
still be allocated to user processes, just not for other in-kernel
purposes.
Ben.
--
Ben Hutchings
Man invented language to satisfy his deep need to complain.
- Lily Tomlin
[toc] | [prev] | [standalone]
Back to top | Article view | linux.debian.kernel
csiph-web