Re: kern/50038: udl (DisplayLink GX-DVI_U2B) alignment fault on earmv6hf NETWALKER

[MOCHIDA Shuji <mochid%netside.co.jp@localhost>]

The following reply was made to PR kern/50038; it has been noted by GNATS.

From: MOCHIDA Shuji <mochid%netside.co.jp@localhost>
To: skrll%netbsd.org@localhost
Cc: gnats-bugs%NetBSD.org@localhost, kern-bug-people%netbsd.org@localhost,
 gnats-admin%netbsd.org@localhost, netbsd-bugs%netbsd.org@localhost
Subject: Re: kern/50038: udl (DisplayLink GX-DVI_U2B) alignment fault on
 earmv6hf NETWALKER
Date: Wed, 16 Nov 2016 22:32:34 +0900 (JST)

 >>   In these functions, (curcpu()->ci_ctrl & CPU_CONTROL_AFLT_ENABLE) is zero.
 
 > We should be running with SCTLR.A =0 and SCTLR.U = 1, i.e.
 > CPU_CONTROL_AFLT_ENABLE unset and CPU_CONTROL_UNAL_ENABLE set, but
 > I think the usb transfer buffer is being marked as device/strongly ordered memory and
 > we get an unaligned access fault because of this.
 
 be32enc(sc->sc_cmd_buf, val) -- sc_cmd_buf is allocated in
 usbdi.c:414 usbd_alloc_buffer() using kmem_alloc()..
 
 -mochid