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Wysocki" , Viresh Kumar , devicetree@vger.kernel.org, srv_heupstream@mediatek.com, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, fan.chen@mediatek.com, linux-mediatek@lists.infradead.org, linux-arm-kernel@lists.infradead.org Subject: Re: [v2,4/4] devfreq: add mediatek cci devfreq Message-ID: <20190408172220.GA28972@roeck-us.net> References: <1553841972-19737-5-git-send-email-andrew-sh.cheng@mediatek.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1553841972-19737-5-git-send-email-andrew-sh.cheng@mediatek.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Mar 29, 2019 at 02:46:12PM +0800, Andrew-sh Cheng wrote: > This adds a devfreq driver for the Cache Coherent Interconnect (CCI) > of the Mediatek MT8183. > > On the MT8183 the CCI is supplied by the same regulator as the LITTLE > cores. The driver is notified when the regulator voltage changes > (driven by cpufreq) and adjusts the CCI frequency to the maximum > possible value. > > Signed-off-by: Andrew-sh.Cheng > --- > drivers/devfreq/Kconfig | 10 ++ > drivers/devfreq/Makefile | 1 + > drivers/devfreq/mt8183-cci-devfreq.c | 235 +++++++++++++++++++++++++++++++++++ > 3 files changed, 246 insertions(+) > create mode 100644 drivers/devfreq/mt8183-cci-devfreq.c > > diff --git a/drivers/devfreq/Kconfig b/drivers/devfreq/Kconfig > index 6a172d3..da2f8ec 100644 > --- a/drivers/devfreq/Kconfig > +++ b/drivers/devfreq/Kconfig > @@ -91,6 +91,16 @@ config ARM_EXYNOS_BUS_DEVFREQ > and adjusts the operating frequencies and voltages with OPP support. > This does not yet operate with optimal voltages. > > +config ARM_MT8183_CCI_DEVFREQ > + tristate "MT8183 CCI DEVFREQ Driver" > + depends on ARM_MEDIATEK_CPUFREQ > + help > + This adds a devfreq driver for Cache Coherent Interconnect > + of Mediatek MT8183, which is shared the same regulator > + with cpu cluster. > + It can track buck voltage and update a proper cci frequency. > + Use notification to get regulator status. > + > config ARM_TEGRA_DEVFREQ > tristate "Tegra DEVFREQ Driver" > depends on ARCH_TEGRA_124_SOC > diff --git a/drivers/devfreq/Makefile b/drivers/devfreq/Makefile > index 32b8d4d..817dde7 100644 > --- a/drivers/devfreq/Makefile > +++ b/drivers/devfreq/Makefile > @@ -9,6 +9,7 @@ obj-$(CONFIG_DEVFREQ_GOV_PASSIVE) += governor_passive.o > > # DEVFREQ Drivers > obj-$(CONFIG_ARM_EXYNOS_BUS_DEVFREQ) += exynos-bus.o > +obj-$(CONFIG_ARM_MT8183_CCI_DEVFREQ) += mt8183-cci-devfreq.o > obj-$(CONFIG_ARM_RK3399_DMC_DEVFREQ) += rk3399_dmc.o > obj-$(CONFIG_ARM_TEGRA_DEVFREQ) += tegra-devfreq.o > > diff --git a/drivers/devfreq/mt8183-cci-devfreq.c b/drivers/devfreq/mt8183-cci-devfreq.c > new file mode 100644 > index 0000000..af82d2e > --- /dev/null > +++ b/drivers/devfreq/mt8183-cci-devfreq.c > @@ -0,0 +1,235 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Copyright (c) 2019 MediaTek Inc. > + */ > + > +#include > +#include > +#include > +#include > +#include > +#include > + > +#include "governor.h" > + > +struct cci_devfreq { > + struct devfreq *devfreq; > + struct regulator *proc_reg; > + unsigned long proc_reg_uV; > + struct clk *cci_clk; > + struct notifier_block nb; > +}; > + > +static int cci_devfreq_regulator_notifier(struct notifier_block *nb, > + unsigned long val, void *data) > +{ > + struct cci_devfreq *cci_df = > + container_of(nb, struct cci_devfreq, nb); > + > + /* deal with reduce frequency */ > + if (val & REGULATOR_EVENT_PRE_VOLTAGE_CHANGE) { > + struct pre_voltage_change_data *pvc_data = data; > + > + if (pvc_data->min_uV < pvc_data->old_uV) { > + cci_df->proc_reg_uV = > + (unsigned long)(pvc_data->min_uV); > + mutex_lock(&cci_df->devfreq->lock); > + update_devfreq(cci_df->devfreq); > + mutex_unlock(&cci_df->devfreq->lock); > + } > + } > + > + if ((val & REGULATOR_EVENT_ABORT_VOLTAGE_CHANGE) && > + ((unsigned long)data > cci_df->proc_reg_uV)) { > + cci_df->proc_reg_uV = (unsigned long)data; > + mutex_lock(&cci_df->devfreq->lock); > + update_devfreq(cci_df->devfreq); > + mutex_unlock(&cci_df->devfreq->lock); > + } > + > + /* deal with increase frequency */ > + if ((val & REGULATOR_EVENT_VOLTAGE_CHANGE) && > + (cci_df->proc_reg_uV < (unsigned long)data)) { > + cci_df->proc_reg_uV = (unsigned long)data; > + mutex_lock(&cci_df->devfreq->lock); > + update_devfreq(cci_df->devfreq); > + mutex_unlock(&cci_df->devfreq->lock); > + } > + > + return 0; > +} > + > +static int mtk_cci_governor_get_target(struct devfreq *devfreq, > + unsigned long *freq) > +{ > + struct cci_devfreq *cci_df; > + struct dev_pm_opp *opp; > + > + cci_df = dev_get_drvdata(devfreq->dev.parent); > + > + /* find available frequency */ > + opp = dev_pm_opp_find_max_freq_by_volt(devfreq->dev.parent, > + cci_df->proc_reg_uV); > + *freq = dev_pm_opp_get_freq(opp); > + > + return 0; > +} > + > +static int mtk_cci_governor_event_handler(struct devfreq *devfreq, > + unsigned int event, void *data) > +{ > + struct cci_devfreq *cci_df; > + struct notifier_block *nb; > + > + cci_df = dev_get_drvdata(devfreq->dev.parent); > + nb = &cci_df->nb; > + > + switch (event) { > + case DEVFREQ_GOV_START: > + case DEVFREQ_GOV_RESUME: > + nb->notifier_call = cci_devfreq_regulator_notifier; > + regulator_register_notifier(cci_df->proc_reg, > + nb); > + break; > + > + case DEVFREQ_GOV_STOP: > + case DEVFREQ_GOV_SUSPEND: > + regulator_unregister_notifier(cci_df->proc_reg, > + nb); > + > + break; > + > + default: > + break; > + } > + > + return 0; > +} > + > +static struct devfreq_governor mtk_cci_devfreq_governor = { > + .name = "mtk_cci_vmon", > + .get_target_freq = mtk_cci_governor_get_target, > + .event_handler = mtk_cci_governor_event_handler, > +}; > + > +static int mtk_cci_devfreq_target(struct device *dev, unsigned long *freq, > + u32 flags) > +{ > + struct cci_devfreq *cci_df = dev_get_drvdata(dev); > + > + if (!cci_df) > + return -EINVAL; > + > + clk_set_rate(cci_df->cci_clk, *freq); > + > + return 0; > +} > + > +static struct devfreq_dev_profile cci_devfreq_profile = { > + .target = mtk_cci_devfreq_target, > +}; > + > +static int mtk_cci_devfreq_probe(struct platform_device *pdev) > +{ > + struct device *cci_dev = &pdev->dev; > + struct cci_devfreq *cci_df; > + int ret; > + > + cci_df = devm_kzalloc(cci_dev, sizeof(*cci_df), GFP_KERNEL); > + if (!cci_df) > + return -ENOMEM; > + > + cci_df->cci_clk = clk_get(cci_dev, "cci_clock"); Should use devm_clk_get(). > + ret = PTR_ERR_OR_ZERO(cci_df->cci_clk); > + if (ret) { > + if (ret != -EPROBE_DEFER) > + dev_err(cci_dev, "failed to get clock for CCI: %d\n", > + ret); > + > + return ret; > + } > + > + cci_df->proc_reg = regulator_get_optional(cci_dev, "proc"); Should use devm_regulator_get_optional(). > + ret = PTR_ERR_OR_ZERO(cci_df->proc_reg); > + if (ret) { > + if (ret != -EPROBE_DEFER) > + dev_err(cci_dev, "failed to get regulator for CCI: %d\n", > + ret); > + > + goto err_put_clk; > + } > + > + ret = dev_pm_opp_of_add_table(&pdev->dev); > + if (ret) { > + dev_err(cci_dev, "Fail to init CCI OPP table\n"); No error code display here ? Not that it really matters, but it is inconsistent with the other error messages. > + goto err_put_reg; > + } > + > + platform_set_drvdata(pdev, cci_df); > + > + cci_df->devfreq = devm_devfreq_add_device(cci_dev, > + &cci_devfreq_profile, > + "mtk_cci_vmon", > + NULL); > + if (IS_ERR(cci_df->devfreq)) { ret = PTR_ERR(cci_df->devfreq); > + dev_err(cci_dev, "cannot create cci devfreq device\n", ret); dev_err(cci_dev, "cannot create cci devfreq device: %d\n", ret); Something like dev_pm_opp_of_remove_table(...); seems to be missing here. > + goto err_put_reg; > + } > + > + return 0; > + > +err_put_reg: > + regulator_put(cci_df->proc_reg); > +err_put_clk: > + clk_put(cci_df->cci_clk); Can be dropped when using devm_ functions above. > + > + return ret; > +} > + > +static const struct of_device_id mediatek_cci_devfreq_of_match[] = { > + { .compatible = "mediatek,mt8183-cci" }, > + { }, > +}; > +MODULE_DEVICE_TABLE(of, mediatek_cci_devfreq_of_match); > + > +static struct platform_driver cci_devfreq_driver = { > + .probe = mtk_cci_devfreq_probe, > + .driver = { > + .name = "mediatek-cci-devfreq", > + .of_match_table = mediatek_cci_devfreq_of_match, If the driver depends on OF, that should be stated in the Kconfig file. Otherwise, of_match_ptr() should be used, and mediatek_cci_devfreq_of_match should be tagged with __maybe_unused (or made conditional with #ifdef). > + }, > +}; > + > +static int __init mtk_cci_devfreq_init(void) > +{ > + int ret; > + > + ret = devfreq_add_governor(&mtk_cci_devfreq_governor); > + if (ret) { > + pr_err("%s: failed to add governor: %d\n", __func__, ret); > + return ret; > + } > + > + ret = platform_driver_register(&cci_devfreq_driver); > + if (ret) > + devfreq_remove_governor(&mtk_cci_devfreq_governor); > + > + return ret; > +} > +module_init(mtk_cci_devfreq_init) > + > +static void __exit mtk_cci_devfreq_exit(void) > +{ > + int ret; > + > + ret = devfreq_remove_governor(&mtk_cci_devfreq_governor); > + if (ret) > + pr_err("%s: failed to remove governor: %d\n", __func__, ret); > + > + platform_driver_unregister(&cci_devfreq_driver); > +} > +module_exit(mtk_cci_devfreq_exit) > + > +MODULE_DESCRIPTION("Mediatek CCI devfreq driver"); > +MODULE_AUTHOR("Andrew-sh.Cheng "); > +MODULE_LICENSE("GPL v2"); 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Mon, 08 Apr 2019 10:22:22 -0700 (PDT) Date: Mon, 8 Apr 2019 10:22:21 -0700 From: Guenter Roeck To: Andrew-sh Cheng Subject: Re: [v2,4/4] devfreq: add mediatek cci devfreq Message-ID: <20190408172220.GA28972@roeck-us.net> References: <1553841972-19737-5-git-send-email-andrew-sh.cheng@mediatek.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1553841972-19737-5-git-send-email-andrew-sh.cheng@mediatek.com> User-Agent: Mutt/1.5.24 (2015-08-30) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190408_102225_096903_8945D950 X-CRM114-Status: GOOD ( 27.38 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , devicetree@vger.kernel.org, srv_heupstream@mediatek.com, linux-pm@vger.kernel.org, Viresh Kumar , "Rafael J. Wysocki" , linux-kernel@vger.kernel.org, Rob Herring , Chanwoo Choi , Kyungmin Park , MyungJoo Ham , linux-mediatek@lists.infradead.org, Matthias Brugger , fan.chen@mediatek.com, linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Fri, Mar 29, 2019 at 02:46:12PM +0800, Andrew-sh Cheng wrote: > This adds a devfreq driver for the Cache Coherent Interconnect (CCI) > of the Mediatek MT8183. > > On the MT8183 the CCI is supplied by the same regulator as the LITTLE > cores. The driver is notified when the regulator voltage changes > (driven by cpufreq) and adjusts the CCI frequency to the maximum > possible value. > > Signed-off-by: Andrew-sh.Cheng > --- > drivers/devfreq/Kconfig | 10 ++ > drivers/devfreq/Makefile | 1 + > drivers/devfreq/mt8183-cci-devfreq.c | 235 +++++++++++++++++++++++++++++++++++ > 3 files changed, 246 insertions(+) > create mode 100644 drivers/devfreq/mt8183-cci-devfreq.c > > diff --git a/drivers/devfreq/Kconfig b/drivers/devfreq/Kconfig > index 6a172d3..da2f8ec 100644 > --- a/drivers/devfreq/Kconfig > +++ b/drivers/devfreq/Kconfig > @@ -91,6 +91,16 @@ config ARM_EXYNOS_BUS_DEVFREQ > and adjusts the operating frequencies and voltages with OPP support. > This does not yet operate with optimal voltages. > > +config ARM_MT8183_CCI_DEVFREQ > + tristate "MT8183 CCI DEVFREQ Driver" > + depends on ARM_MEDIATEK_CPUFREQ > + help > + This adds a devfreq driver for Cache Coherent Interconnect > + of Mediatek MT8183, which is shared the same regulator > + with cpu cluster. > + It can track buck voltage and update a proper cci frequency. > + Use notification to get regulator status. > + > config ARM_TEGRA_DEVFREQ > tristate "Tegra DEVFREQ Driver" > depends on ARCH_TEGRA_124_SOC > diff --git a/drivers/devfreq/Makefile b/drivers/devfreq/Makefile > index 32b8d4d..817dde7 100644 > --- a/drivers/devfreq/Makefile > +++ b/drivers/devfreq/Makefile > @@ -9,6 +9,7 @@ obj-$(CONFIG_DEVFREQ_GOV_PASSIVE) += governor_passive.o > > # DEVFREQ Drivers > obj-$(CONFIG_ARM_EXYNOS_BUS_DEVFREQ) += exynos-bus.o > +obj-$(CONFIG_ARM_MT8183_CCI_DEVFREQ) += mt8183-cci-devfreq.o > obj-$(CONFIG_ARM_RK3399_DMC_DEVFREQ) += rk3399_dmc.o > obj-$(CONFIG_ARM_TEGRA_DEVFREQ) += tegra-devfreq.o > > diff --git a/drivers/devfreq/mt8183-cci-devfreq.c b/drivers/devfreq/mt8183-cci-devfreq.c > new file mode 100644 > index 0000000..af82d2e > --- /dev/null > +++ b/drivers/devfreq/mt8183-cci-devfreq.c > @@ -0,0 +1,235 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Copyright (c) 2019 MediaTek Inc. > + */ > + > +#include > +#include > +#include > +#include > +#include > +#include > + > +#include "governor.h" > + > +struct cci_devfreq { > + struct devfreq *devfreq; > + struct regulator *proc_reg; > + unsigned long proc_reg_uV; > + struct clk *cci_clk; > + struct notifier_block nb; > +}; > + > +static int cci_devfreq_regulator_notifier(struct notifier_block *nb, > + unsigned long val, void *data) > +{ > + struct cci_devfreq *cci_df = > + container_of(nb, struct cci_devfreq, nb); > + > + /* deal with reduce frequency */ > + if (val & REGULATOR_EVENT_PRE_VOLTAGE_CHANGE) { > + struct pre_voltage_change_data *pvc_data = data; > + > + if (pvc_data->min_uV < pvc_data->old_uV) { > + cci_df->proc_reg_uV = > + (unsigned long)(pvc_data->min_uV); > + mutex_lock(&cci_df->devfreq->lock); > + update_devfreq(cci_df->devfreq); > + mutex_unlock(&cci_df->devfreq->lock); > + } > + } > + > + if ((val & REGULATOR_EVENT_ABORT_VOLTAGE_CHANGE) && > + ((unsigned long)data > cci_df->proc_reg_uV)) { > + cci_df->proc_reg_uV = (unsigned long)data; > + mutex_lock(&cci_df->devfreq->lock); > + update_devfreq(cci_df->devfreq); > + mutex_unlock(&cci_df->devfreq->lock); > + } > + > + /* deal with increase frequency */ > + if ((val & REGULATOR_EVENT_VOLTAGE_CHANGE) && > + (cci_df->proc_reg_uV < (unsigned long)data)) { > + cci_df->proc_reg_uV = (unsigned long)data; > + mutex_lock(&cci_df->devfreq->lock); > + update_devfreq(cci_df->devfreq); > + mutex_unlock(&cci_df->devfreq->lock); > + } > + > + return 0; > +} > + > +static int mtk_cci_governor_get_target(struct devfreq *devfreq, > + unsigned long *freq) > +{ > + struct cci_devfreq *cci_df; > + struct dev_pm_opp *opp; > + > + cci_df = dev_get_drvdata(devfreq->dev.parent); > + > + /* find available frequency */ > + opp = dev_pm_opp_find_max_freq_by_volt(devfreq->dev.parent, > + cci_df->proc_reg_uV); > + *freq = dev_pm_opp_get_freq(opp); > + > + return 0; > +} > + > +static int mtk_cci_governor_event_handler(struct devfreq *devfreq, > + unsigned int event, void *data) > +{ > + struct cci_devfreq *cci_df; > + struct notifier_block *nb; > + > + cci_df = dev_get_drvdata(devfreq->dev.parent); > + nb = &cci_df->nb; > + > + switch (event) { > + case DEVFREQ_GOV_START: > + case DEVFREQ_GOV_RESUME: > + nb->notifier_call = cci_devfreq_regulator_notifier; > + regulator_register_notifier(cci_df->proc_reg, > + nb); > + break; > + > + case DEVFREQ_GOV_STOP: > + case DEVFREQ_GOV_SUSPEND: > + regulator_unregister_notifier(cci_df->proc_reg, > + nb); > + > + break; > + > + default: > + break; > + } > + > + return 0; > +} > + > +static struct devfreq_governor mtk_cci_devfreq_governor = { > + .name = "mtk_cci_vmon", > + .get_target_freq = mtk_cci_governor_get_target, > + .event_handler = mtk_cci_governor_event_handler, > +}; > + > +static int mtk_cci_devfreq_target(struct device *dev, unsigned long *freq, > + u32 flags) > +{ > + struct cci_devfreq *cci_df = dev_get_drvdata(dev); > + > + if (!cci_df) > + return -EINVAL; > + > + clk_set_rate(cci_df->cci_clk, *freq); > + > + return 0; > +} > + > +static struct devfreq_dev_profile cci_devfreq_profile = { > + .target = mtk_cci_devfreq_target, > +}; > + > +static int mtk_cci_devfreq_probe(struct platform_device *pdev) > +{ > + struct device *cci_dev = &pdev->dev; > + struct cci_devfreq *cci_df; > + int ret; > + > + cci_df = devm_kzalloc(cci_dev, sizeof(*cci_df), GFP_KERNEL); > + if (!cci_df) > + return -ENOMEM; > + > + cci_df->cci_clk = clk_get(cci_dev, "cci_clock"); Should use devm_clk_get(). > + ret = PTR_ERR_OR_ZERO(cci_df->cci_clk); > + if (ret) { > + if (ret != -EPROBE_DEFER) > + dev_err(cci_dev, "failed to get clock for CCI: %d\n", > + ret); > + > + return ret; > + } > + > + cci_df->proc_reg = regulator_get_optional(cci_dev, "proc"); Should use devm_regulator_get_optional(). > + ret = PTR_ERR_OR_ZERO(cci_df->proc_reg); > + if (ret) { > + if (ret != -EPROBE_DEFER) > + dev_err(cci_dev, "failed to get regulator for CCI: %d\n", > + ret); > + > + goto err_put_clk; > + } > + > + ret = dev_pm_opp_of_add_table(&pdev->dev); > + if (ret) { > + dev_err(cci_dev, "Fail to init CCI OPP table\n"); No error code display here ? Not that it really matters, but it is inconsistent with the other error messages. > + goto err_put_reg; > + } > + > + platform_set_drvdata(pdev, cci_df); > + > + cci_df->devfreq = devm_devfreq_add_device(cci_dev, > + &cci_devfreq_profile, > + "mtk_cci_vmon", > + NULL); > + if (IS_ERR(cci_df->devfreq)) { ret = PTR_ERR(cci_df->devfreq); > + dev_err(cci_dev, "cannot create cci devfreq device\n", ret); dev_err(cci_dev, "cannot create cci devfreq device: %d\n", ret); Something like dev_pm_opp_of_remove_table(...); seems to be missing here. > + goto err_put_reg; > + } > + > + return 0; > + > +err_put_reg: > + regulator_put(cci_df->proc_reg); > +err_put_clk: > + clk_put(cci_df->cci_clk); Can be dropped when using devm_ functions above. > + > + return ret; > +} > + > +static const struct of_device_id mediatek_cci_devfreq_of_match[] = { > + { .compatible = "mediatek,mt8183-cci" }, > + { }, > +}; > +MODULE_DEVICE_TABLE(of, mediatek_cci_devfreq_of_match); > + > +static struct platform_driver cci_devfreq_driver = { > + .probe = mtk_cci_devfreq_probe, > + .driver = { > + .name = "mediatek-cci-devfreq", > + .of_match_table = mediatek_cci_devfreq_of_match, If the driver depends on OF, that should be stated in the Kconfig file. Otherwise, of_match_ptr() should be used, and mediatek_cci_devfreq_of_match should be tagged with __maybe_unused (or made conditional with #ifdef). > + }, > +}; > + > +static int __init mtk_cci_devfreq_init(void) > +{ > + int ret; > + > + ret = devfreq_add_governor(&mtk_cci_devfreq_governor); > + if (ret) { > + pr_err("%s: failed to add governor: %d\n", __func__, ret); > + return ret; > + } > + > + ret = platform_driver_register(&cci_devfreq_driver); > + if (ret) > + devfreq_remove_governor(&mtk_cci_devfreq_governor); > + > + return ret; > +} > +module_init(mtk_cci_devfreq_init) > + > +static void __exit mtk_cci_devfreq_exit(void) > +{ > + int ret; > + > + ret = devfreq_remove_governor(&mtk_cci_devfreq_governor); > + if (ret) > + pr_err("%s: failed to remove governor: %d\n", __func__, ret); > + > + platform_driver_unregister(&cci_devfreq_driver); > +} > +module_exit(mtk_cci_devfreq_exit) > + > +MODULE_DESCRIPTION("Mediatek CCI devfreq driver"); > +MODULE_AUTHOR("Andrew-sh.Cheng "); > +MODULE_LICENSE("GPL v2"); _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel