hw/omap_gpmc: Add comment about FIFOTHRESHOLDSTATUS bit

Promote the remark about why we handle FIFOTHRESHOLDSTATUS the
way we do from the commit message of de8af7fe0 to a comment in
the code.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Andrzej Zaborowski <andrew.zaborowski@intel.com>
This commit is contained in:
Peter Maydell 2011-09-17 19:51:48 +01:00 committed by Andrzej Zaborowski
parent d85a1302a9
commit 7196345549

View File

@ -569,6 +569,13 @@ static uint64_t omap_gpmc_read(void *opaque, target_phys_addr_t addr,
case 0x1ec: /* GPMC_PREFETCH_CONTROL */
return s->prefetch.startengine;
case 0x1f0: /* GPMC_PREFETCH_STATUS */
/* NB: The OMAP3 TRM is inconsistent about whether the GPMC
* FIFOTHRESHOLDSTATUS bit should be set when
* FIFOPOINTER > FIFOTHRESHOLD or when it is >= FIFOTHRESHOLD.
* Apparently the underlying functional spec from which the TRM was
* created states that the behaviour is ">=", and this also
* makes more conceptual sense.
*/
return (s->prefetch.fifopointer << 24) |
((s->prefetch.fifopointer >=
((s->prefetch.config1 >> 8) & 0x7f) ? 1 : 0) << 16) |