OMAP3: workaround for ARM Cortex-A8 erratum 725233
authorSiarhei Siamashka <siarhei.siamashka@gmail.com>
Wed, 24 Feb 2010 04:56:36 +0000 (23:56 -0500)
committerTom Rix <Tom.Rix@windriver.com>
Wed, 24 Feb 2010 16:55:16 +0000 (10:55 -0600)
commit42d97d08838d4e010d80c92ad1300c426320dd18
treefaa5afbbc77665469e3c62e270c8638a7982db3a
parentcdb53ab078c1b88a52ebd142a9d7ca2da4abc2f6
OMAP3: workaround for ARM Cortex-A8 erratum 725233

725233: PLD instructions executed with PLD data forwarding
enabled can result in a processor deadlock

This deadlock can happen when NEON load instructions are used together
with cache preload instructions (PLD). The problematic conditions
can be triggered in-the-wild by NEON optimized functions from pixman
library (http://cgit.freedesktop.org/pixman), which perform dynamic
adjustment of prefetch distance.

The workaround disables PLD data forwarding by setting PLD_FWD bit
in L2 Cache Auxiliary Control Register as recommended in ARM Cortex-A8
errata list.

The deadlock can only happen on r1pX revisions of Cortex-A8 (used in
OMAP34xx/OMAP35xx). Performance impact of the workaround is practically
non-existant.

Signed-off-by: Siarhei Siamashka <siarhei.siamashka@gmail.com>
Signed-off-by: Sandeep Paulraj <s-paulraj@ti.com>
cpu/arm_cortexa8/omap3/board.c