Re: [PATCH 2/4] ARM OMAP2+ GPMC: always program GPMCFCLKDIVIDER
From: Robert Abel
Date: Mon Feb 16 2015 - 15:09:34 EST
On 16 Feb 2015 18:10, Tony Lindgren wrote:
* Robert ABEL <rabel@xxxxxxxxxxxxxxxxxxxxxxx> [150216 07:52]:Maybe to clarify: This is only affects asynchronous accesses with
WAITREADMONITORING and/or WAITWRITEMONITORING enabled. Regular
asynchronous accesses without WAIT pin monitoring were never affected to
begin with and are not affected by this change.
GPMC uses GPMCFCLKDIVIDER during synchronous as well as asynchronous accesses
Do you have some test case that gets fixed by this? Or does this
in conjunction with WAITMONITORINGTIME. Thus, it's wrong to only program it for
synchronous accesses. Remove the conditional.
fix some regression?
The reason why I'm asking is that AFAIK we've had async access
working all along?
I don't have an off-hand test case and seeing as the current
implementation is faulty, it's probable nobody actively uses this
feature. Cf. OMAP35xx TRM (SPRUF98X) pp. 1103. Basically,
WAITMONITORINGTIME extends the number of cycles from the end of WAIT
asserted to when the data is provided/sampled and the read/write access
(should) take place. While this behavior is esoteric, it's not a reason
not to fix this oversight.
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