coresight: tmc: Fix byte-address alignment for RRP
authorLeo Yan <leo.yan@linaro.org>
Thu, 20 Sep 2018 19:18:02 +0000 (13:18 -0600)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Mon, 25 Nov 2019 08:52:53 +0000 (09:52 +0100)
commit8c3d23bd86884379902b9de8c0461a5f52ed3b4c
tree03228d411533211501c854e4abf93ecd1154ee9c
parent6b32261826811cb53a49cc679c982c0733de3a51
coresight: tmc: Fix byte-address alignment for RRP

[ Upstream commit e7753f3937610633a540f2be81be87531f96ff04 ]

>From the comment in the code, it claims the requirement for byte-address
alignment for RRP register: 'for 32-bit, 64-bit and 128-bit wide trace
memory, the four LSBs must be 0s. For 256-bit wide trace memory, the
five LSBs must be 0s'.  This isn't consistent with the program, the
program sets five LSBs as zeros for 32/64/128-bit wide trace memory and
set six LSBs zeros for 256-bit wide trace memory.

After checking with the CoreSight Trace Memory Controller technical
reference manual (ARM DDI 0461B, section 3.3.4 RAM Read Pointer
Register), it proves the comment is right and the program does wrong
setting.

This patch fixes byte-address alignment for RRP by following correct
definition in the technical reference manual.

Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Mike Leach <mike.leach@linaro.org>
Signed-off-by: Leo Yan <leo.yan@linaro.org>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
drivers/hwtracing/coresight/coresight-tmc-etf.c