From: Amit Sunil Dhamne <amit.sunil.dhamne@xilinx.com> To: ard.biesheuvel@linaro.org, mingo@kernel.org, gregkh@linuxfoundation.org, matt@codeblueprint.co.uk, sudeep.holla@arm.com, hkallweit1@gmail.com, keescook@chromium.org, dmitry.torokhov@gmail.com, michal.simek@xilinx.com Cc: rajanv@xilinx.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, tejasp@xilinx.com, jollys@xilinx.com, Rajan Vaja <rajan.vaja@xilinx.com>, Amit Sunil Dhamne <amit.sunil.dhamne@xilinx.com> Subject: [PATCH] drivers: soc: xilinx: Call InitFinalize from late_initcall_sync instead of probe Date: Wed, 22 Jul 2020 16:25:51 -0700 [thread overview] Message-ID: <20200722232551.29549-1-amit.sunil.dhamne@xilinx.com> (raw) From: Rajan Vaja <rajan.vaja@xilinx.com> Initially all devices are in power up state. Firmware expect that processor should call InitFinalize API once it have requested devices which are required so that it can turn off all unused devices and save power. From Linux, PM driver calls InitFinalize to inform the firmware that it can power down the unused devices. Upon InitFinalize() call firmware power downs all unused devices. There are chances that PM driver is probed along with or before other device drivers. So in that case some of the devices may not be requested from firmware which is done by genpd driver. Due to that firmware will consider those devices as unused and firmware will power down those devices. Later when any device driver is probed, genpd driver will ask firmware to power up that device using request node API. So for those devices, power transition will be like on->off->on which creates unnecessary power glitch to those devices. To avoid such unnecessary power transitions and as ideal behavior InitFinalize should be called after all drivers are probed. So call InitFinalize from late_initcall_sync. Signed-off-by: Rajan Vaja <rajan.vaja@xilinx.com> Signed-off-by: Amit Sunil Dhamne <amit.sunil.dhamne@xilinx.com> --- drivers/soc/xilinx/zynqmp_power.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/soc/xilinx/zynqmp_power.c b/drivers/soc/xilinx/zynqmp_power.c index 31ff49fcd078..fa05cf12d5f3 100644 --- a/drivers/soc/xilinx/zynqmp_power.c +++ b/drivers/soc/xilinx/zynqmp_power.c @@ -178,7 +178,6 @@ static int zynqmp_pm_probe(struct platform_device *pdev) u32 pm_api_version; struct mbox_client *client; - zynqmp_pm_init_finalize(); zynqmp_pm_get_api_version(&pm_api_version); /* Check PM API version number */ @@ -246,6 +245,13 @@ static int zynqmp_pm_remove(struct platform_device *pdev) return 0; } +static int __init do_init_finalize(void) +{ + return zynqmp_pm_init_finalize(); +} + +late_initcall_sync(do_init_finalize); + static const struct of_device_id pm_of_match[] = { { .compatible = "xlnx,zynqmp-power", }, { /* end of table */ }, -- 2.23.0 This email and any attachments are intended for the sole use of the named recipient(s) and contain(s) confidential information that may be proprietary, privileged or copyrighted under applicable law. If you are not the intended recipient, do not read, copy, or forward this email message or any attachments. Delete this email message and any attachments immediately.
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From: Amit Sunil Dhamne <amit.sunil.dhamne@xilinx.com> To: ard.biesheuvel@linaro.org, mingo@kernel.org, gregkh@linuxfoundation.org, matt@codeblueprint.co.uk, sudeep.holla@arm.com, hkallweit1@gmail.com, keescook@chromium.org, dmitry.torokhov@gmail.com, michal.simek@xilinx.com Cc: Amit Sunil Dhamne <amit.sunil.dhamne@xilinx.com>, Rajan Vaja <rajan.vaja@xilinx.com>, tejasp@xilinx.com, linux-kernel@vger.kernel.org, jollys@xilinx.com, rajanv@xilinx.com, linux-arm-kernel@lists.infradead.org Subject: [PATCH] drivers: soc: xilinx: Call InitFinalize from late_initcall_sync instead of probe Date: Wed, 22 Jul 2020 16:25:51 -0700 [thread overview] Message-ID: <20200722232551.29549-1-amit.sunil.dhamne@xilinx.com> (raw) From: Rajan Vaja <rajan.vaja@xilinx.com> Initially all devices are in power up state. Firmware expect that processor should call InitFinalize API once it have requested devices which are required so that it can turn off all unused devices and save power. From Linux, PM driver calls InitFinalize to inform the firmware that it can power down the unused devices. Upon InitFinalize() call firmware power downs all unused devices. There are chances that PM driver is probed along with or before other device drivers. So in that case some of the devices may not be requested from firmware which is done by genpd driver. Due to that firmware will consider those devices as unused and firmware will power down those devices. Later when any device driver is probed, genpd driver will ask firmware to power up that device using request node API. So for those devices, power transition will be like on->off->on which creates unnecessary power glitch to those devices. To avoid such unnecessary power transitions and as ideal behavior InitFinalize should be called after all drivers are probed. So call InitFinalize from late_initcall_sync. Signed-off-by: Rajan Vaja <rajan.vaja@xilinx.com> Signed-off-by: Amit Sunil Dhamne <amit.sunil.dhamne@xilinx.com> --- drivers/soc/xilinx/zynqmp_power.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/soc/xilinx/zynqmp_power.c b/drivers/soc/xilinx/zynqmp_power.c index 31ff49fcd078..fa05cf12d5f3 100644 --- a/drivers/soc/xilinx/zynqmp_power.c +++ b/drivers/soc/xilinx/zynqmp_power.c @@ -178,7 +178,6 @@ static int zynqmp_pm_probe(struct platform_device *pdev) u32 pm_api_version; struct mbox_client *client; - zynqmp_pm_init_finalize(); zynqmp_pm_get_api_version(&pm_api_version); /* Check PM API version number */ @@ -246,6 +245,13 @@ static int zynqmp_pm_remove(struct platform_device *pdev) return 0; } +static int __init do_init_finalize(void) +{ + return zynqmp_pm_init_finalize(); +} + +late_initcall_sync(do_init_finalize); + static const struct of_device_id pm_of_match[] = { { .compatible = "xlnx,zynqmp-power", }, { /* end of table */ }, -- 2.23.0 This email and any attachments are intended for the sole use of the named recipient(s) and contain(s) confidential information that may be proprietary, privileged or copyrighted under applicable law. If you are not the intended recipient, do not read, copy, or forward this email message or any attachments. Delete this email message and any attachments immediately. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next reply other threads:[~2020-07-22 23:26 UTC|newest] Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-07-22 23:25 Amit Sunil Dhamne [this message] 2020-07-22 23:25 ` [PATCH] drivers: soc: xilinx: Call InitFinalize from late_initcall_sync instead of probe Amit Sunil Dhamne 2020-07-30 5:32 ` Michal Simek 2020-07-30 5:32 ` Michal Simek
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