CVS commit: src/sys/dev/ic

["Izumi Tsutsui" <tsutsui%netbsd.org@localhost>]

Module Name:    src
Committed By:   tsutsui
Date:           Mon Jan 10 11:18:15 UTC 2011

Modified Files:
        src/sys/dev/ic: ahcisata_core.c

Log Message:
Don't call bus_dmamap_load(9) and bus_dmamap_sync(9) on command xfers
if (AT_READ|AT_WRITE) in ata_c->flags is set but ata_c->bcount is zero.
Someone actually tries to put such a command and it causes
DIAGNOSTIC panic in x86/bus_dma.c:_bus_dmamap_sync().
I think bus_dma(9) API itself may allow calls with mapsize==0
but there are many MD code that asserts offset>=mapsize or len==0.

The problem is reported and fix is confirmed by Takuro KUBOTA
with XEN DOM0 kernel (which has options DIAGNOSTIC).


To generate a diff of this commit:
cvs rdiff -u -r1.30 -r1.31 src/sys/dev/ic/ahcisata_core.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.