From: jason.hui@linaro.org (Jason Liu)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] ARM: iMX5: Don't enable DPLL if it already enabled
Date: Fri, 5 Aug 2011 23:34:32 +0800 [thread overview]
Message-ID: <1312558472-30590-1-git-send-email-jason.hui@linaro.org> (raw)
If the DPLL is already enabled, don't try to enable it again.
Since write to the DPLL control register will make the DPLL
reset and which will cause some issues when some child module
are sourced from this DPLL.
Signed-off-by: Jason Liu <jason.hui@linaro.org>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
---
arch/arm/mach-mx5/clock-mx51-mx53.c | 6 +++++-
1 files changed, 5 insertions(+), 1 deletions(-)
diff --git a/arch/arm/mach-mx5/clock-mx51-mx53.c b/arch/arm/mach-mx5/clock-mx51-mx53.c
index 7f20308..f7bf996 100644
--- a/arch/arm/mach-mx5/clock-mx51-mx53.c
+++ b/arch/arm/mach-mx5/clock-mx51-mx53.c
@@ -271,7 +271,11 @@ static int _clk_pll_enable(struct clk *clk)
int i = 0;
pllbase = _get_pll_base(clk);
- reg = __raw_readl(pllbase + MXC_PLL_DP_CTL) | MXC_PLL_DP_CTL_UPEN;
+ reg = __raw_readl(pllbase + MXC_PLL_DP_CTL);
+ if (reg & MXC_PLL_DP_CTL_UPEN)
+ return 0;
+
+ reg |= MXC_PLL_DP_CTL_UPEN;
__raw_writel(reg, pllbase + MXC_PLL_DP_CTL);
/* Wait for lock */
--
1.7.0.4
reply other threads:[~2011-08-05 15:34 UTC|newest]
Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1312558472-30590-1-git-send-email-jason.hui@linaro.org \
--to=jason.hui@linaro.org \
--cc=linux-arm-kernel@lists.infradead.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).