PR/54486 CVS commit: [netbsd-9] src/sys

["Martin Husemann" <martin%netbsd.org@localhost>]

The following reply was made to PR kern/54486; it has been noted by GNATS.

From: "Martin Husemann" <martin%netbsd.org@localhost>
To: gnats-bugs%gnats.NetBSD.org@localhost
Cc: 
Subject: PR/54486 CVS commit: [netbsd-9] src/sys
Date: Sun, 1 Sep 2019 14:03:03 +0000

 Module Name:	src
 Committed By:	martin
 Date:		Sun Sep  1 14:03:02 UTC 2019
 
 Modified Files:
 	src/sys/arch/arm/conf [netbsd-9]: Makefile.arm
 	src/sys/dev/usb [netbsd-9]: if_axe.c
 
 Log Message:
 Pull up following revision(s) (requested by rin in ticket #146):
 
 	sys/arch/arm/conf/Makefile.arm: revision 1.50
 	sys/dev/usb/if_axe.c: revision 1.120
 
 PR kern/54486
 
 Workaround for alignment faults on ARMv6+, at least occur with
 axe(4) and athn(4) drivers.
 
 For ARMv6+, unaligned access is enabled by default. However, it
 cannot be used for non-cacheable memory, which is used as DMA
 buffers. This results in alignment faults above. A real fix is
 to use cacheable memory as DMA buffers. However, it breaks some
 drivers, awge(4) and vchiq(4) at least.
 
 Until we figure out problems and fix them, we choose a fail-safe
 workaround here; forbid unaligned memory access for whole kernel.
 Affects on performance is negligibly small as far as we can see.
 
 XXX
 pullup netbsd-9
 
  -
 
 PR kern/54486
 Revert workaround introduced in rev 1.94:
 http://cvsweb.netbsd.org/bsdweb.cgi/src/sys/dev/usb/if_axe.c#rev1.94
 
 This is a problem specific to ARMv6+, and addressed by
 arch/arm/conf/Makefile.arm rev 1.50:
 http://cvsweb.netbsd.org/bsdweb.cgi/src/sys/arch/arm/conf/Makefile.arm#rev1.50
 
 XXX
 pullup netbsd-9
 
 
 To generate a diff of this commit:
 cvs rdiff -u -r1.49 -r1.49.4.1 src/sys/arch/arm/conf/Makefile.arm
 cvs rdiff -u -r1.102.2.1 -r1.102.2.2 src/sys/dev/usb/if_axe.c
 
 Please note that diffs are not public domain; they are subject to the
 copyright notices on the relevant files.