From: Krzysztof Kozlowski <k.kozlowski@samsung.com> To: Stephen Boyd <stephen.boyd@linaro.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>, Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>, hzpeterchen@gmail.com, Ulf Hansson <ulf.hansson@linaro.org>, Sebastian Reichel <sre@kernel.org>, Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>, David Woodhouse <dwmw2@infradead.org>, Javier Martinez Canillas <javier@osg.samsung.com>, linux-kernel@vger.kernel.org, linux-mmc@vger.kernel.org, linux-pm@vger.kernel.or, Alan Stern <stern@rowland.harvard.edu>, linux-usb@vger.kernel.org, Rob Herring <robh+dt@kernel.org>, Pawel Moll <pawel.moll@arm.com>, Mark Rutland <mark.rutland@arm.com>, Ian Campbell <ijc+devicetree@hellion.org.uk>, Kumar Gala <galak@codeaurora.org>, Kukjin Kim <kgene@kernel.org>, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-samsung-soc@vger.kernel.org Subject: Re: [PATCH v3 09/12] EXAMPLE CODE: usb: port: Parse pwrseq phandle from Device Tree Date: Wed, 01 Jun 2016 11:06:46 +0200 [thread overview] Message-ID: <574EA5A6.3090102@samsung.com> (raw) In-Reply-To: <146477144362.1485.3331887341591876278@sboyd-linaro> On 06/01/2016 10:57 AM, Stephen Boyd wrote: > Quoting Krzysztof Kozlowski (2016-06-01 01:02:18) >> Parse usb-pwrseq property from Device Tree to get the phandle to pwrseq >> device. The pwrseq device will be used by USB hub to cycle the power >> before activating ports. >> >> Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com> > > Drive by review comment. > > I was hoping this would help me with a problem I'm having where I have a > hub (smsc4604) that needs to be taken out of reset before my HSIC > controller sends a USB reset to it, but it seems this is more about > doing some sort of power on sequence after enumeration? This example is not finished but from what you wrote, it might suit your needs as well. The power sequence is done before enumeration because without it, the device won't enumerate. The exact power sequence for USB devices has to be still developed. Comments are welcomed. >> diff --git a/drivers/usb/core/port.c b/drivers/usb/core/port.c >> index 460c855be0d0..89b9bdfc7061 100644 >> --- a/drivers/usb/core/port.c >> +++ b/drivers/usb/core/port.c >> @@ -18,6 +18,8 @@ >> >> #include <linux/slab.h> >> #include <linux/pm_qos.h> >> +#include <linux/pwrseq.h> >> +#include <linux/usb/of.h> >> >> #include "hub.h" >> >> @@ -526,6 +528,14 @@ int usb_hub_create_port_device(struct usb_hub *hub, int port1) >> return retval; >> } >> >> + port_dev->dev.of_node = usb_of_get_child_node(hdev->dev.parent->of_node, >> + port1); >> + port_dev->pwrseq = pwrseq_alloc(&port_dev->dev, "usb-pwrseq"); >> + if (IS_ERR(port_dev->pwrseq)) { >> + device_unregister(&port_dev->dev); >> + return PTR_ERR(port_dev->pwrseq); > > Are we certain that port_dev hasn't been freed at this point? We just > called device_unregister() on it, so it seems safer to save away the > return value before calling device_unregister() here. Right, good point. Thanks for feedback. Best regards, Krzysztof
WARNING: multiple messages have this Message-ID (diff)
From: k.kozlowski@samsung.com (Krzysztof Kozlowski) To: linux-arm-kernel@lists.infradead.org Subject: [PATCH v3 09/12] EXAMPLE CODE: usb: port: Parse pwrseq phandle from Device Tree Date: Wed, 01 Jun 2016 11:06:46 +0200 [thread overview] Message-ID: <574EA5A6.3090102@samsung.com> (raw) In-Reply-To: <146477144362.1485.3331887341591876278@sboyd-linaro> On 06/01/2016 10:57 AM, Stephen Boyd wrote: > Quoting Krzysztof Kozlowski (2016-06-01 01:02:18) >> Parse usb-pwrseq property from Device Tree to get the phandle to pwrseq >> device. The pwrseq device will be used by USB hub to cycle the power >> before activating ports. >> >> Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com> > > Drive by review comment. > > I was hoping this would help me with a problem I'm having where I have a > hub (smsc4604) that needs to be taken out of reset before my HSIC > controller sends a USB reset to it, but it seems this is more about > doing some sort of power on sequence after enumeration? This example is not finished but from what you wrote, it might suit your needs as well. The power sequence is done before enumeration because without it, the device won't enumerate. The exact power sequence for USB devices has to be still developed. Comments are welcomed. >> diff --git a/drivers/usb/core/port.c b/drivers/usb/core/port.c >> index 460c855be0d0..89b9bdfc7061 100644 >> --- a/drivers/usb/core/port.c >> +++ b/drivers/usb/core/port.c >> @@ -18,6 +18,8 @@ >> >> #include <linux/slab.h> >> #include <linux/pm_qos.h> >> +#include <linux/pwrseq.h> >> +#include <linux/usb/of.h> >> >> #include "hub.h" >> >> @@ -526,6 +528,14 @@ int usb_hub_create_port_device(struct usb_hub *hub, int port1) >> return retval; >> } >> >> + port_dev->dev.of_node = usb_of_get_child_node(hdev->dev.parent->of_node, >> + port1); >> + port_dev->pwrseq = pwrseq_alloc(&port_dev->dev, "usb-pwrseq"); >> + if (IS_ERR(port_dev->pwrseq)) { >> + device_unregister(&port_dev->dev); >> + return PTR_ERR(port_dev->pwrseq); > > Are we certain that port_dev hasn't been freed at this point? We just > called device_unregister() on it, so it seems safer to save away the > return value before calling device_unregister() here. Right, good point. Thanks for feedback. Best regards, Krzysztof
next prev parent reply other threads:[~2016-06-01 9:06 UTC|newest] Thread overview: 66+ messages / expand[flat|nested] mbox.gz Atom feed top 2016-06-01 8:02 [PATCH v3 00/12] usb/mmc/power: Generic power sequence (and fix USB/LAN when TFTP booting) Krzysztof Kozlowski 2016-06-01 8:02 ` Krzysztof Kozlowski 2016-06-01 8:02 ` [PATCH v3 01/12] power/mmc: Move pwrseq drivers to power/pwrseq Krzysztof Kozlowski 2016-06-01 8:02 ` Krzysztof Kozlowski 2016-06-01 8:02 ` [PATCH v3 02/12] MAINTAINERS: Retain Ulf Hansson as the same maintainer of pwrseq Krzysztof Kozlowski 2016-06-01 8:02 ` Krzysztof Kozlowski 2016-06-01 8:02 ` [PATCH v3 03/12] power: pwrseq: Enable COMPILE_TEST for drivers Krzysztof Kozlowski 2016-06-01 8:02 ` Krzysztof Kozlowski 2016-06-01 8:02 ` [PATCH v3 04/12] power: pwrseq: Remove mmc prefix from mmc_pwrseq Krzysztof Kozlowski 2016-06-01 8:02 ` Krzysztof Kozlowski 2016-06-01 8:02 ` [PATCH v3 05/12] power: pwrseq: Generalize mmc_pwrseq operations by removing mmc prefix Krzysztof Kozlowski 2016-06-01 8:02 ` Krzysztof Kozlowski 2016-06-01 8:02 ` [PATCH v3 06/12] power: pwrseq: simple: Add support for regulator and generic property Krzysztof Kozlowski 2016-06-01 8:02 ` Krzysztof Kozlowski 2016-06-03 2:02 ` Rob Herring 2016-06-03 2:02 ` Rob Herring 2016-06-03 12:35 ` Krzysztof Kozlowski 2016-06-03 12:35 ` Krzysztof Kozlowski 2016-06-06 3:22 ` Peter Chen 2016-06-06 3:22 ` Peter Chen 2016-06-07 9:29 ` Krzysztof Kozlowski 2016-06-07 9:29 ` Krzysztof Kozlowski 2016-06-07 9:29 ` Krzysztof Kozlowski 2016-06-08 19:03 ` Rob Herring 2016-06-08 19:03 ` Rob Herring 2016-06-09 2:34 ` Chen-Yu Tsai 2016-06-09 2:34 ` Chen-Yu Tsai 2016-06-09 2:34 ` Chen-Yu Tsai 2016-06-09 5:11 ` Krzysztof Kozlowski 2016-06-09 5:11 ` Krzysztof Kozlowski 2016-06-09 5:11 ` Krzysztof Kozlowski 2016-06-01 8:02 ` [PATCH v3 07/12] power: pwrseq: Add support for USB hubs with external power Krzysztof Kozlowski 2016-06-01 8:02 ` Krzysztof Kozlowski 2016-06-01 8:02 ` [PATCH v3 08/12] usb: hub: Handle deferred probe Krzysztof Kozlowski 2016-06-01 8:02 ` Krzysztof Kozlowski 2016-06-01 8:02 ` [PATCH v3 09/12] EXAMPLE CODE: usb: port: Parse pwrseq phandle from Device Tree Krzysztof Kozlowski 2016-06-01 8:02 ` Krzysztof Kozlowski 2016-06-01 8:57 ` Stephen Boyd 2016-06-01 8:57 ` Stephen Boyd 2016-06-01 8:57 ` Stephen Boyd 2016-06-01 9:06 ` Krzysztof Kozlowski [this message] 2016-06-01 9:06 ` Krzysztof Kozlowski 2016-06-01 12:05 ` Peter Chen 2016-06-01 12:05 ` Peter Chen 2016-06-01 18:16 ` Stephen Boyd 2016-06-01 18:16 ` Stephen Boyd 2016-06-02 1:24 ` Peter Chen 2016-06-02 1:24 ` Peter Chen 2016-06-02 23:59 ` Stephen Boyd 2016-06-02 23:59 ` Stephen Boyd 2016-06-01 8:02 ` [PATCH v3 10/12] EXAMPLE CODE: usb: hub: Power sequence the ports on activation Krzysztof Kozlowski 2016-06-01 8:02 ` Krzysztof Kozlowski 2016-06-01 8:02 ` [PATCH v3 11/12] ARM: dts: exynos: Switch the buck8 to GPIO mode on Odroid U3 Krzysztof Kozlowski 2016-06-01 8:02 ` Krzysztof Kozlowski 2016-06-01 8:02 ` [PATCH v3 12/12] ARM: dts: exynos: Fix LAN and HUB after bootloader initialization " Krzysztof Kozlowski 2016-06-01 8:02 ` Krzysztof Kozlowski 2016-06-01 11:59 ` Peter Chen 2016-06-01 11:59 ` Peter Chen 2016-06-02 7:26 ` Krzysztof Kozlowski 2016-06-02 7:26 ` Krzysztof Kozlowski 2016-06-02 7:58 ` Peter Chen 2016-06-02 7:58 ` Peter Chen 2016-06-06 20:43 ` [PATCH v3 00/12] usb/mmc/power: Generic power sequence (and fix USB/LAN when TFTP booting) Heiko Stübner 2016-06-06 20:43 ` Heiko Stübner 2016-06-07 6:03 ` Krzysztof Kozlowski 2016-06-07 6:03 ` Krzysztof Kozlowski
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