Messages in this thread | | | From | Stephen Boyd <> | Subject | Re: [PATCH 2/2] clk: imx: imx7d: remove clks_init_on array | Date | Fri, 31 Aug 2018 10:57:56 -0700 |
| |
Quoting Jerome Forissier (2018-08-31 01:01:44) > > > On 08/31/2018 03:29 AM, Stephen Boyd wrote: > > Quoting Peng Fan (2018-08-12 18:15:41) > >> Hi Anson, > >> > >>>>> -----Original Message----- > >>>>> From: Anson Huang > >>>>> Sent: 2018年8月8日 12:39 > >>>>> To: shawnguo@kernel.org; s.hauer@pengutronix.de; > >>>>> kernel@pengutronix.de; Fabio Estevam <fabio.estevam@nxp.com>; > >>>>> mturquette@baylibre.com; sboyd@kernel.org; > >>>>> linux-arm-kernel@lists.infradead.org; > >>>>> linux-clk@vger.kernel.org; linux-kernel@vger.kernel.org > >>>>> Cc: dl-linux-imx <linux-imx@nxp.com> > >>>>> Subject: [PATCH 2/2] clk: imx: imx7d: remove clks_init_on array > >>>>> > >>>>> Clock framework will enable those clocks registered with > >>>>> CLK_IS_CRITICAL flag, so no need to have clks_init_on array during > >>>>> clock > >>>> initialization now. > >>>> > >>>> Will it be more flexible to parse dts saying "critical-clocks = <xxx>" > >>>> or "init-on-arrary=<xxx>" > >>>> and enable those clocks? > >>> > >>> Parsing the clocks arrays from dtb is another way of enabling critical clocks, but > >>> for current i.MX6/7 platforms, we implement it in same way as most of other > >>> SoCs, currently I did NOT see any necessity of putting them in dtb, just adding > >>> flag during clock registering is more simple, if there is any special requirement > >>> for different clocks set to be enabled, then we can add support to enable the > >>> method of parsing critical-clocks from dtb. Just my two cents. > >> > >> Thinking about OP-TEE want to use one device, but it's clocks are registered > >> by Linux, because there is no module in Linux side use it, it will shutdown the clock, > >> which cause OP-TEE could not access the device. > >> > >> Then people have to modify clk code to add CLK_IS_CRITICAL flag to make sure > >> the clocks are not shutdown by Linux. > >> > >> However adding a new property in clk node and let driver code parse the dts, > >> there is no need to modify clk driver code when OP-TEE needs another device clock. > >> > > > > If OP-TEE needs linux to keep things on then why can't the OP-TEE driver > > in Linux probe, acquire clocks, and keep the clks enabled forever? > > Sounds reasonable, but how could this be done without introducing > platform-specific stuff in the OP-TEE driver? >
Why is that a goal?
| |