From: Shawn Guo <shawnguo@kernel.org>
To: Stefan Wahren <stefan.wahren@i2se.com>
Cc: Victorien Vedrine <victorien.vedrine@ophrys.net>,
linux-kernel@vger.kernel.org, linux-clk@vger.kernel.org,
sboyd@codeaurora.org, mturquette@baylibre.com,
shawn.guo@linaro.org,
"Fabio.Estevam@freescale.com" <Fabio.Estevam@freescale.com>,
Marek Vasut <marex@denx.de>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH v2] clk:mxs: Fix bug on frequency divider
Date: Thu, 24 Sep 2015 05:17:38 -0700 [thread overview]
Message-ID: <20150924121738.GP3529@tiger> (raw)
In-Reply-To: <55FBBB6D.4010805@i2se.com>
On Fri, Sep 18, 2015 at 09:21:17AM +0200, Stefan Wahren wrote:
> +Shawn's new address
> +linux-arm-kernel
>
> > On drivers/clk/mxs/clk-frac.c, the function clk_frac_round_rate returned a bad
> > result. The division before multiplication computes a wrong value ; the
> > calculation is inverted to fix the problem. The second issue is that the exact
> > rate have decimals and they are truncate. The consequence is that the function
> > clk_frac_set_rate (which use the result of clk_frac_round_rate) computes a
> > wrong value for the register (the rate generated can be closer to the desired
> > rate). The correction is : if there is decimal to the result, it is rounded to
> > the next larger integer.
> > On drivers/clk/mxs/clk-frac.c, the function clk_frac_recalc_rate returned
> > a bad result. The multiplication is made before the division to compute a
> > correct value.
> >
> > Signed-off-by: Victorien Vedrine <victorien.vedrine@ophrys.net>
Acked-by: Shawn Guo <shawnguo@kernel.org>
next prev parent reply other threads:[~2015-09-24 12:17 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-07-31 16:24 [PATCH] clk:mxs: Fix bug on frequency divider Victorien Vedrine
2015-07-31 17:34 ` Stephen Boyd
2015-08-19 10:29 ` victorien.vedrine
2015-08-31 8:45 ` [PATCH v2] " Victorien Vedrine
2015-09-16 14:16 ` Stefan Wahren
2015-09-18 7:21 ` Stefan Wahren
2015-09-24 12:17 ` Shawn Guo [this message]
2015-10-01 22:25 ` Stephen Boyd
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