[REGRESSION] drm/etnaviv: command buffer outside valid memory window
Russell King - ARM Linux admin
linux at armlinux.org.uk
Thu Jun 27 16:48:18 UTC 2019
On Thu, Jun 27, 2019 at 04:49:30PM +0200, Lucas Stach wrote:
> Am Donnerstag, den 27.06.2019, 15:32 +0100 schrieb Russell King - ARM Linux admin:
> > On Thu, Jun 27, 2019 at 11:04:17AM +0100, Russell King - ARM Linux admin wrote:
> > > On Thu, Jun 27, 2019 at 11:20:15AM +0200, Lucas Stach wrote:
> > > > Am Samstag, den 22.06.2019, 17:16 +0100 schrieb Russell King - ARM Linux admin:
> > > > > While updating my various systems for the TCP SACK issue, I notice
> > > > > that while most platforms are happy, the Cubox-i4 is not. During
> > > > > boot, we get:
> > > > >
> > > > > [ 0.000000] cma: Reserved 256 MiB at 0x30000000
> > > > > ...
> > > > > [ 0.000000] Kernel command line: console=ttymxc0,115200n8 console=tty1 video=mxcfb0:dev=hdmi root=/dev/nfs rw cma=256M ahci_imx.hotplug=1 splash resume=/dev/sda1
> > > > > [ 0.000000] Dentry cache hash table entries: 131072 (order: 7, 524288 bytes)
> > > > > [ 0.000000] Inode-cache hash table entries: 65536 (order: 6, 262144 bytes)
> > > > > [ 0.000000] Memory: 1790972K/2097152K available (8471K kernel code, 693K rwdata, 2844K rodata, 500K init, 8062K bss, 44036K reserved, 262144K cma-reserved, 1310720K highmem)
> > > > > ...
> > > > > [ 13.101098] etnaviv-gpu 130000.gpu: command buffer outside valid memory window
> > > > > [ 13.171963] etnaviv-gpu 134000.gpu: command buffer outside valid memory window
> > > >
> > > > Yes, that's a regression due to different default CMA area placement
> > > > and etnaviv not being smart enough to move the linear window to the
> > > > right offset.
> > >
> > > As it's a user visible regression, it needs fixing, either by reverting
> > > the changes that caused it or by some other issue. In the kernel, the
> > > policy is "if a bug fix causes a regression, the bug fix was itself
> > > wrong". We don't fix one person's bug if it causes a regression for
> > > someone else.
> > >
> > > Please resolve the acknowledged regression.
> The regression is caused due to a different CMA placement, which is
> outside of the control of etnaviv. If you can point to the commit
> causing this change in placement we could work with the
> authors/maintainers of this code to get rid of the regression.
> Currently I don't have the bandwidth to pinpoint the offending code
Ok, thanks for the explanation.
Well, the problem has become weirder. I'm unable to reproduce the hang
now - the only change has been to add your patch for the unload issue,
as well as temporarily disabling lightdm's startup at boot (which is
now back as it was.) Odd.
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTC broadband for 0.8mile line in suburbia: sync at 12.1Mbps down 622kbps up
According to speedtest.net: 11.9Mbps down 500kbps up
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