wct4xxp: __t4_frame_in and __t4_framer_out slowdowns.

This is a partial revert of r10234 "wct4xxp: __t4_framer_in and
__t4_framer_out speedups."

There were some platform + firmware version combinations that would fail to
properly configure the framer with the aforementioned speedups. The originally
reported sympton was that interrupts would fail to start and while
troubleshooting I also saw cases where one of the spans would stay in alarm
after starting. By adding in additional reads to the version register, the
overall process of writing / reading from the framer control registers is
slowed down which increases reliability.

This change does *not* affect the main path of TDM data which is DMAed
directly into buffers in host memory and are not read / written to / from
framer registers directly.

Reported-and-Tested-by: Vahan Yerkanian <vahan@arminco.com>
Signed-off-by: Shaun Ruffell <sruffell@digium.com>

Origin: http://svnview.digium.com/svn/dahdi?view=rev&rev=10559

git-svn-id: http://svn.asterisk.org/svn/dahdi/linux/branches/2.6@10565 a0bf4364-ded3-4de4-8d8a-66a801d63aff
This commit is contained in:
Shaun Ruffell 2012-03-21 19:11:49 +00:00
parent 6009f56f8b
commit a2bfd1d4c2

View File

@ -670,11 +670,12 @@ static unsigned int __t4_framer_in(const struct t4 *wc, int unit,
val = ((unit & 0x3) << 8) | (addr & 0xff) | haddr;
writel(val, wc_laddr);
/* readl(wc_version); */
readl(wc_version);
writel(val | WC_LFRMR_CS | WC_LREAD, wc_laddr);
readl(wc_version);
ret = readb(wc_ldata);
writel(val, wc_laddr);
readl(wc_version);
return ret;
}
@ -700,11 +701,13 @@ static void __t4_framer_out(const struct t4 *wc, int unit, const u8 addr,
val = ((unit & 0x3) << 8) | (addr & 0xff) | haddr;
writel(val, wc_laddr);
readl(wc_version);
writel(value, wc_ldata);
readl(wc_version);
writel(val | WC_LFRMR_CS | WC_LWRITE, wc_laddr);
/* readl(wc_version); */
readl(wc_version);
writel(val, wc_laddr);
readl(wc_version);
}
static void t4_framer_out(struct t4 *wc, int unit,