On 11/06/2014 08:09 PM, Dmitry Torokhov wrote:
On Thu, Nov 06, 2014 at 03:51:02PM +0200, Grygorii Strashko wrote:Device's clocks need to be enabled always at probing time if !CONFIG_PM_RUNTIME - in that way, device will become accesible and, later, its clocks can be disabled/enabled during system suspend/resume by using pm_clk_suspend/pm_clk_resume APIs. But now, the clocks management code doesn't enable clocks when clocks are being registered per-device by using pm_clk_add/_clk(). So, update pm_clk_acquire(), which is called from pm_clk_add/_clk(), to enable clock always if !CONFIG_PM_RUNTIME. Also, Platform PM domains drivers will not have to add code like below each time they need to handle the case when !CONFIG_PM_RUNTIME [1 - 3]: if (!IS_ENABLED(CONFIG_PM_RUNTIME)) { ret = pm_clk_resume(dev); if (ret) { dev_err(dev, "pm_clk_resume failed %d\n", ret); goto clk_err; }; } [1] https://lkml.org/lkml/2014/10/3/306 [2] https://lkml.org/lkml/2014/10/16/305 [3] https://lkml.org/lkml/2014/10/20/249 CC: Santosh Shilimkar <ssantosh@xxxxxxxxxx> CC: Kevin Hilman <khilman@xxxxxxxxxx> CC: Ulf Hansson <ulf.hansson@xxxxxxxxxx> CC: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> CC: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx> CC: Philipp Zabel <p.zabel@xxxxxxxxxxxxxx> CC: Caesar Wang <caesar.wang@xxxxxxxxxxxxxx> Signed-off-by: Grygorii Strashko <grygorii.strashko@xxxxxx> --- Hi, I marked it as RFC, because: Generic clock manipulation PM callbacks can be used for any device for which list of clocks need to be maintained - and it doesn't mean that this framework need to be always connected to GPD/Runtime PM or used during suspend resume. Also, for DT-use case - it doesn't perform any actions (except clk_prepare) on clocks by itself and only by request from framework's consumer. For example, it can be reused by Power domain/controller drivers like: - Rockchip RK3288 PM Domain (https://lkml.org/lkml/2014/11/6/30) - IMX.6 PU power domain (http://www.spinics.net/lists/arm-kernel/msg360709.html) to maintain list of clocks for GPD itself and these clocks should not be enabled by default, because they are used to power on/off Power domain in a specific way: - enable all clocks assigned to PD - power on/off PD - disable all clocks assigned to PD. After this patch it will be impossible to reuse Generic clock manipulation PM callbacks in cases described above.I'd rather keep it separate and concentrate on making pm_clk* code working with the power management core. Individual drivers can easily keep list of their clocks for whatever additional purpose they need without involving pm_clk* API.
In general, I'm ok with this patch for Keystone 2 proposes, just added some notes about introduced limitations. And all current users of pm_clk* APIs will not regress with this patch, because they will go through different code path if !CONFIG_PM_RUNTIME. Regards, -grygorii -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
