From mboxrd@z Thu Jan 1 00:00:00 1970 From: jerome.forissier@linaro.org (Jerome Forissier) Date: Fri, 31 Aug 2018 10:01:44 +0200 Subject: [PATCH 2/2] clk: imx: imx7d: remove clks_init_on array In-Reply-To: <153567894721.93865.4092113232222931488@swboyd.mtv.corp.google.com> References: <1533703167-26583-1-git-send-email-Anson.Huang@nxp.com> <1533703167-26583-2-git-send-email-Anson.Huang@nxp.com> <153567894721.93865.4092113232222931488@swboyd.mtv.corp.google.com> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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?8?8? 12:39 >>>>> To: shawnguo at kernel.org; s.hauer at pengutronix.de; >>>>> kernel at pengutronix.de; Fabio Estevam ; >>>>> mturquette at baylibre.com; sboyd at kernel.org; >>>>> linux-arm-kernel at lists.infradead.org; >>>>> linux-clk at vger.kernel.org; linux-kernel at vger.kernel.org >>>>> Cc: dl-linux-imx >>>>> 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 = " >>>> or "init-on-arrary=" >>>> 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? > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel at lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel >