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author | Scott McNutt <smcnutt@psyent.com> | 2010-04-01 00:00:56 -0400 |
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committer | Scott McNutt <smcnutt@psyent.com> | 2010-04-02 12:28:41 -0400 |
commit | d8bc0a2889700ba063598de6d4e7d135360b537e (patch) | |
tree | 78412b80d2152b3690723179897fc5113c108b8e /cpu/mpc8220 | |
parent | ed2941578480d30b413e081b6f1a5675d4afd9e2 (diff) | |
download | u-boot-imx-d8bc0a2889700ba063598de6d4e7d135360b537e.zip u-boot-imx-d8bc0a2889700ba063598de6d4e7d135360b537e.tar.gz u-boot-imx-d8bc0a2889700ba063598de6d4e7d135360b537e.tar.bz2 |
nios2: Reload timer count in reset_timer()
When the timestamp is incremented via interrupt and the interrupt
period is greater than 1 msec, successive calls to get_timer() can
produce inaccurate timing since the interrupts are asynchronous
to the timing loop. For example, with an interrupt period of 10 msec
two successive calls to get_timer() could indicate an elapsed time
of 10 msec after only several hundred usecs -- depending on when
the next interrupt actually occurs. This behavior can cause
reliability issues with components such as CFI and NAND.
This can be remedied by calling reset_timer() prior to establishing
the base timestamp with get_timer(0), provided reset_timer()
resets the hardware timer (rather than simply resetting only the
timestamp). This has the effect of synchronizing the interrupts
(and the advance of the timestamp) with the timing loop.
Signed-off-by: Scott McNutt <smcnutt@psyent.com>
Diffstat (limited to 'cpu/mpc8220')
0 files changed, 0 insertions, 0 deletions