[PATCH v2] omap2: fix DPLL_FREQSEL calculation

On 2011-01-20, Felipe Balbi [off-list ref] wrote:

scripts/get_maintainer.pl would've helped you getting a better Cc
list. I'm adding linux-omap and lakml

Thanks.

After investigating the issue further it seems that I had it
backwards. The value of "n" is the value to divide by, not the value
that goes in the register. This means that it is _dpll_test_fint()
that is doing it incorrectly. Here is a new version of the patch to
fix the right function.



This patch fixes the calculation of the internal frequency. The value
of "n" is the actual divider to use.

This patch is against linux-next-20110120.

Signed-off-by: John Ogness <john.ogness@linutronix.de>
---
 arch/arm/mach-omap2/clkt_dpll.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm/mach-omap2/clkt_dpll.c b/arch/arm/mach-omap2/clkt_dpll.c
index 337392c..acb7ae5 100644
--- a/arch/arm/mach-omap2/clkt_dpll.c
+++ b/arch/arm/mach-omap2/clkt_dpll.c

@@ -77,7 +77,7 @@ static int _dpll_test_fint(struct clk *clk, u8 n)
 	dd = clk->dpll_data;
 
 	/* DPLL divider must result in a valid jitter correction val */
-	fint = clk->parent->rate / (n + 1);
+	fint = clk->parent->rate / n;
 	if (fint < DPLL_FINT_BAND1_MIN) {
 
 		pr_debug("rejecting n=%d due to Fint failure, "

On Thu, Jan 20, 2011 at 03:29:50PM +0100, John Ogness wrote:

On 2011-01-20, Felipe Balbi [off-list ref] wrote:

quoted

scripts/get_maintainer.pl would've helped you getting a better Cc
list. I'm adding linux-omap and lakml

Thanks.

After investigating the issue further it seems that I had it
backwards. The value of "n" is the value to divide by, not the value
that goes in the register. This means that it is _dpll_test_fint()
that is doing it incorrectly. Here is a new version of the patch to
fix the right function.

you might want to look at Documentation/SubmittingPatches before sending
these patches. If anyone applies this patch of yours the commitlog will
have all the comments you've made above. Generally, patches are
"standalone" emails, without a discussion on them, if you want to add
comments which aren't supposed to go into commit log, then do so after
the tear line (---) and before the diff --git line; that way, git will
know it must drop that part of the comments.

-- 
balbi