From mboxrd@z Thu Jan 1 00:00:00 1970 From: jagan@amarulasolutions.com (Jagan Teki) Date: Thu, 25 Oct 2018 16:25:59 +0530 Subject: [PATCH v2 02/15] clk: sunxi-ng: Add check for minimal rate to NKM PLLs In-Reply-To: <20181024180436.5n3i3z6h2yezc4cv@flea> References: <20181023155035.9101-1-jagan@amarulasolutions.com> <20181023155035.9101-3-jagan@amarulasolutions.com> <20181024180436.5n3i3z6h2yezc4cv@flea> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Wed, Oct 24, 2018 at 11:34 PM Maxime Ripard wrote: > > On Tue, Oct 23, 2018 at 09:20:22PM +0530, Jagan Teki wrote: > > Some NKM PLLs doesn't work well when their output clock rate is set below > > certain rate. > > > > So, add support for minimal rate for relevant PLLs. > > > > Signed-off-by: Jagan Teki > > --- > > Changes for v2: > > - new patch > > > > drivers/clk/sunxi-ng/ccu_nkm.c | 7 +++++++ > > drivers/clk/sunxi-ng/ccu_nkm.h | 1 + > > 2 files changed, 8 insertions(+) > > > > diff --git a/drivers/clk/sunxi-ng/ccu_nkm.c b/drivers/clk/sunxi-ng/ccu_nkm.c > > index 841840e35e61..d17539dc88dd 100644 > > --- a/drivers/clk/sunxi-ng/ccu_nkm.c > > +++ b/drivers/clk/sunxi-ng/ccu_nkm.c > > @@ -125,6 +125,13 @@ static unsigned long ccu_nkm_round_rate(struct ccu_mux_internal *mux, > > if (nkm->common.features & CCU_FEATURE_FIXED_POSTDIV) > > rate *= nkm->fixed_post_div; > > > > + if (rate < nkm->min_rate) { > > + rate = nkm->min_rate; > > + if (nkm->common.features & CCU_FEATURE_FIXED_POSTDIV) > > + rate /= nkm->fixed_post_div; > > I'm not sure this is right. Is the post divider taken into account to > calculate the minimum, or is the minimum on the rate before the fixed > post divider. Since we are returning from here, we need to take care post div which is actually doing at the end of round_rate. > > How did you test this? I've not used this on PLL_MIPI atleast, so I didn't test this.