From: Geert Uytterhoeven <geert+renesas@glider.be> To: Miquel Raynal <miquel.raynal@bootlin.com>, Richard Weinberger <richard@nod.at>, Vignesh Raghavendra <vigneshr@ti.com> Cc: "Rafael J . Wysocki" <rjw@rjwysocki.net>, Kevin Hilman <khilman@kernel.org>, Ulf Hansson <ulf.hansson@linaro.org>, Chris Brandt <chris.brandt@renesas.com>, linux-mtd@lists.infradead.org, linux-pm@vger.kernel.org, linux-renesas-soc@vger.kernel.org, linux-kernel@vger.kernel.org, Geert Uytterhoeven <geert+renesas@glider.be> Subject: [PATCH resend] mtd: maps: physmap: Add minimal Runtime PM support Date: Wed, 15 Jan 2020 14:13:23 +0100 [thread overview] Message-ID: <20200115131323.6883-1-geert+renesas@glider.be> (raw) Add minimal runtime PM support (enable on probe, disable on remove), to ensure proper operation with a parent device that uses runtime PM. This is needed on systems where the FLASH is connected to a bus controller that is contained in a PM domain and/or has a gateable functional clock. In such cases, before accessing any device connected to the external bus, the PM domain must be powered up, and/or the functional clock must be enabled, which is typically handled through runtime PM by the bus controller driver. An example of this is the Renesas APE6-EVM development board, which has an Ethernet controller and a CFI FLASH connected to the Bus State Controller (BSC) of an R-Mobile APE6 SoC. As long as the Ethernet driver, which had Runtime PM support since commit 3a611e26e958b037 ("net/smsc911x: Add minimal runtime PM support"), keeps the BSC powered, accessing the FLASH works. When the ethernet node in r8a73a4-ape6evm.dts is disabled, the BSC is never powered up, and the kernel crashes when trying to access the FLASH: Unhandled fault: imprecise external abort (0x1406) at 0x00000000 pgd = (ptrval) [00000000] *pgd=7fef2835 Internal error: : 1406 [#1] SMP ARM CPU: 0 PID: 122 Comm: hd Tainted: G W 5.5.0-rc1-ape6evm-00814-g38ca966db25b9dbd-dirty #136 Hardware name: Generic R8A73A4 (Flattened Device Tree) PC is at chip_ready+0x12c/0x380 LR is at chip_ready+0x10c/0x380 Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> --- Probably the device should be powered down after probing, and powered up/down on-demand in the various {get,put}_chip() functions. However, that is an optimization which touches more intimidate details of the internal MTD API, and can be done later. --- drivers/mtd/maps/physmap-core.c | 20 +++++++++++++++----- 1 file changed, 15 insertions(+), 5 deletions(-) diff --git a/drivers/mtd/maps/physmap-core.c b/drivers/mtd/maps/physmap-core.c index a9f7964e2edb6668..8f7f966fa9a7ee8a 100644 --- a/drivers/mtd/maps/physmap-core.c +++ b/drivers/mtd/maps/physmap-core.c @@ -38,6 +38,7 @@ #include <linux/mtd/cfi_endian.h> #include <linux/io.h> #include <linux/of_device.h> +#include <linux/pm_runtime.h> #include <linux/gpio/consumer.h> #include "physmap-gemini.h" @@ -64,16 +65,16 @@ static int physmap_flash_remove(struct platform_device *dev) { struct physmap_flash_info *info; struct physmap_flash_data *physmap_data; - int i, err; + int i, err = 0; info = platform_get_drvdata(dev); if (!info) - return 0; + goto out; if (info->cmtd) { err = mtd_device_unregister(info->cmtd); if (err) - return err; + goto out; if (info->cmtd != info->mtds[0]) mtd_concat_destroy(info->cmtd); @@ -88,7 +89,10 @@ static int physmap_flash_remove(struct platform_device *dev) if (physmap_data && physmap_data->exit) physmap_data->exit(dev); - return 0; +out: + pm_runtime_put(&dev->dev); + pm_runtime_disable(&dev->dev); + return err; } static void physmap_set_vpp(struct map_info *map, int state) @@ -484,13 +488,19 @@ static int physmap_flash_probe(struct platform_device *dev) return -EINVAL; } + pm_runtime_enable(&dev->dev); + pm_runtime_get_sync(&dev->dev); + if (dev->dev.of_node) err = physmap_flash_of_init(dev); else err = physmap_flash_pdata_init(dev); - if (err) + if (err) { + pm_runtime_put(&dev->dev); + pm_runtime_disable(&dev->dev); return err; + } for (i = 0; i < info->nmaps; i++) { struct resource *res; -- 2.17.1
WARNING: multiple messages have this Message-ID (diff)
From: Geert Uytterhoeven <geert+renesas@glider.be> To: Miquel Raynal <miquel.raynal@bootlin.com>, Richard Weinberger <richard@nod.at>, Vignesh Raghavendra <vigneshr@ti.com> Cc: Ulf Hansson <ulf.hansson@linaro.org>, Geert Uytterhoeven <geert+renesas@glider.be>, linux-pm@vger.kernel.org, Kevin Hilman <khilman@kernel.org>, "Rafael J . Wysocki" <rjw@rjwysocki.net>, linux-kernel@vger.kernel.org, linux-renesas-soc@vger.kernel.org, Chris Brandt <chris.brandt@renesas.com>, linux-mtd@lists.infradead.org Subject: [PATCH resend] mtd: maps: physmap: Add minimal Runtime PM support Date: Wed, 15 Jan 2020 14:13:23 +0100 [thread overview] Message-ID: <20200115131323.6883-1-geert+renesas@glider.be> (raw) Add minimal runtime PM support (enable on probe, disable on remove), to ensure proper operation with a parent device that uses runtime PM. This is needed on systems where the FLASH is connected to a bus controller that is contained in a PM domain and/or has a gateable functional clock. In such cases, before accessing any device connected to the external bus, the PM domain must be powered up, and/or the functional clock must be enabled, which is typically handled through runtime PM by the bus controller driver. An example of this is the Renesas APE6-EVM development board, which has an Ethernet controller and a CFI FLASH connected to the Bus State Controller (BSC) of an R-Mobile APE6 SoC. As long as the Ethernet driver, which had Runtime PM support since commit 3a611e26e958b037 ("net/smsc911x: Add minimal runtime PM support"), keeps the BSC powered, accessing the FLASH works. When the ethernet node in r8a73a4-ape6evm.dts is disabled, the BSC is never powered up, and the kernel crashes when trying to access the FLASH: Unhandled fault: imprecise external abort (0x1406) at 0x00000000 pgd = (ptrval) [00000000] *pgd=7fef2835 Internal error: : 1406 [#1] SMP ARM CPU: 0 PID: 122 Comm: hd Tainted: G W 5.5.0-rc1-ape6evm-00814-g38ca966db25b9dbd-dirty #136 Hardware name: Generic R8A73A4 (Flattened Device Tree) PC is at chip_ready+0x12c/0x380 LR is at chip_ready+0x10c/0x380 Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> --- Probably the device should be powered down after probing, and powered up/down on-demand in the various {get,put}_chip() functions. However, that is an optimization which touches more intimidate details of the internal MTD API, and can be done later. --- drivers/mtd/maps/physmap-core.c | 20 +++++++++++++++----- 1 file changed, 15 insertions(+), 5 deletions(-) diff --git a/drivers/mtd/maps/physmap-core.c b/drivers/mtd/maps/physmap-core.c index a9f7964e2edb6668..8f7f966fa9a7ee8a 100644 --- a/drivers/mtd/maps/physmap-core.c +++ b/drivers/mtd/maps/physmap-core.c @@ -38,6 +38,7 @@ #include <linux/mtd/cfi_endian.h> #include <linux/io.h> #include <linux/of_device.h> +#include <linux/pm_runtime.h> #include <linux/gpio/consumer.h> #include "physmap-gemini.h" @@ -64,16 +65,16 @@ static int physmap_flash_remove(struct platform_device *dev) { struct physmap_flash_info *info; struct physmap_flash_data *physmap_data; - int i, err; + int i, err = 0; info = platform_get_drvdata(dev); if (!info) - return 0; + goto out; if (info->cmtd) { err = mtd_device_unregister(info->cmtd); if (err) - return err; + goto out; if (info->cmtd != info->mtds[0]) mtd_concat_destroy(info->cmtd); @@ -88,7 +89,10 @@ static int physmap_flash_remove(struct platform_device *dev) if (physmap_data && physmap_data->exit) physmap_data->exit(dev); - return 0; +out: + pm_runtime_put(&dev->dev); + pm_runtime_disable(&dev->dev); + return err; } static void physmap_set_vpp(struct map_info *map, int state) @@ -484,13 +488,19 @@ static int physmap_flash_probe(struct platform_device *dev) return -EINVAL; } + pm_runtime_enable(&dev->dev); + pm_runtime_get_sync(&dev->dev); + if (dev->dev.of_node) err = physmap_flash_of_init(dev); else err = physmap_flash_pdata_init(dev); - if (err) + if (err) { + pm_runtime_put(&dev->dev); + pm_runtime_disable(&dev->dev); return err; + } for (i = 0; i < info->nmaps; i++) { struct resource *res; -- 2.17.1 ______________________________________________________ Linux MTD discussion mailing list http://lists.infradead.org/mailman/listinfo/linux-mtd/
next reply other threads:[~2020-01-15 13:13 UTC|newest] Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-01-15 13:13 Geert Uytterhoeven [this message] 2020-01-15 13:13 ` [PATCH resend] mtd: maps: physmap: Add minimal Runtime PM support Geert Uytterhoeven 2020-01-15 15:42 ` Niklas Söderlund 2020-01-15 15:42 ` Niklas Söderlund 2020-01-15 23:48 ` Kevin Hilman 2020-01-15 23:48 ` Kevin Hilman
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