Re: [PATCH v2] console: Don't prefer first registered if DT specifies stdout-path
On Monday, 17 October 2016 19:39:57 BST Andreas Schwab wrote: > On Okt 17 2016, Paul Burton wrote: > > Could you share the device tree from your system? > > This is the contents of chosen/linux,stdout-path on the systems I have: > > chosen/linux,stdout-path > "/pci@f000/ATY,SnowyParent@10/ATY,Snowy_A@0" > > chosen/linux,stdout-path > "/pci@0,f000/NVDA,Parent@10/NVDA,Display-B@1" > > Is that what you need? There is also chosen/stdout, but no > aliases/stdout. > > Andreas. Hi Andreas, I think I see the problem & I'm hoping this patch will fix it: https://lkml.org/lkml/2016/10/18/142 Could you give it a try & let me know? Thanks, Paul signature.asc Description: This is a digitally signed message part.
Re: [PATCH v2] console: Don't prefer first registered if DT specifies stdout-path
On Okt 17 2016, Paul Burton wrote: > Could you share the device tree from your system? This is the contents of chosen/linux,stdout-path on the systems I have: chosen/linux,stdout-path "/pci@f000/ATY,SnowyParent@10/ATY,Snowy_A@0" chosen/linux,stdout-path "/pci@0,f000/NVDA,Parent@10/NVDA,Display-B@1" Is that what you need? There is also chosen/stdout, but no aliases/stdout. Andreas. -- Andreas Schwab, sch...@linux-m68k.org GPG Key fingerprint = 58CA 54C7 6D53 942B 1756 01D3 44D5 214B 8276 4ED5 "And now for something completely different."
Re: [PATCH v2] console: Don't prefer first registered if DT specifies stdout-path
On Sunday, 16 October 2016 20:07:18 BST Andreas Schwab wrote: > On Aug 09 2016, Paul Burton wrote: > > Fix this by not automatically preferring the first registered console if > > one is specified by the device tree. This allows consoles to be > > registered but not enabled, and once the driver for the console selected > > by stdout-path calls of_console_check() the driver will be added to the > > list of preferred consoles before any other console has been enabled. > > When that console is then registered via register_console() it will be > > enabled as expected. > > This breaks the console on PowerMac. There is no output and it panics > eventually. > > Andreas. Hi Andreas, Could you share the device tree from your system? Thanks, Paul signature.asc Description: This is a digitally signed message part.
Re: [PATCH v2] console: Don't prefer first registered if DT specifies stdout-path
On Aug 09 2016, Paul Burton wrote: > Fix this by not automatically preferring the first registered console if > one is specified by the device tree. This allows consoles to be > registered but not enabled, and once the driver for the console selected > by stdout-path calls of_console_check() the driver will be added to the > list of preferred consoles before any other console has been enabled. > When that console is then registered via register_console() it will be > enabled as expected. This breaks the console on PowerMac. There is no output and it panics eventually. Andreas. -- Andreas Schwab, sch...@linux-m68k.org GPG Key fingerprint = 58CA 54C7 6D53 942B 1756 01D3 44D5 214B 8276 4ED5 "And now for something completely different."
Re: [PATCH v2] console: Don't prefer first registered if DT specifies stdout-path
On Tue, 9 Aug 2016 16:19:37 +0100 Paul Burton wrote: > If a device tree specifies a preferred device for kernel console output > via the stdout-path or linux,stdout-path chosen node properties or the > stdout alias then the kernel ought to honor it & output the kernel > console to that device. As it stands, this isn't the case. Whilst we > parse the stdout-path properties & set an of_stdout variable from > of_alias_scan(), and use that from of_console_check() to determine > whether to add a console device as a preferred console whilst > registering it, we also prefer the first registered console if no other > has been selected at the time of its registration. > > This means that if a console other than the one the device tree selects > via stdout-path is registered first, we will switch to using it & when > the stdout-path console is later registered the call to > add_preferred_console() via of_console_check() is too late to do > anything useful. In practice this seems to mean that we switch to the > dummy console device fairly early & see no further console output: > > Console: colour dummy device 80x25 > console [tty0] enabled > bootconsole [ns16550a0] disabled > > Fix this by not automatically preferring the first registered console if > one is specified by the device tree. This allows consoles to be > registered but not enabled, and once the driver for the console selected > by stdout-path calls of_console_check() the driver will be added to the > list of preferred consoles before any other console has been enabled. > When that console is then registered via register_console() it will be > enabled as expected. Looks reasonable. Could you please do `grep -r stdout-path Documentation' and check that everything therein is complete, accurate and necessary?
