From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nagarjuna Kristam Subject: Re: [Patch V3 03/18] phy: tegra: xusb: Add usb-role-switch support Date: Wed, 29 Jan 2020 14:45:38 +0530 Message-ID: References: <1577704195-2535-1-git-send-email-nkristam@nvidia.com> <1577704195-2535-4-git-send-email-nkristam@nvidia.com> <20200128173244.GA2293590@ulmo> Mime-Version: 1.0 Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20200128173244.GA2293590@ulmo> Content-Language: en-US Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Thierry Reding Cc: balbi-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, gregkh-hQyY1W1yCW8ekmWlsbkhG0B+6BGkLq7r@public.gmane.org, jonathanh-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org, mark.rutland-5wv7dgnIgG8@public.gmane.org, robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, kishon-l0cyMroinI0@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-usb-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-tegra@vger.kernel.org On 28-01-2020 23:02, Thierry Reding wrote: > On Mon, Dec 30, 2019 at 04:39:40PM +0530, Nagarjuna Kristam wrote: >> If usb-role-switch property is present in USB 2 port, register >> usb-role-switch to receive usb role changes. >> >> Signed-off-by: Nagarjuna Kristam >> --- >> V3: >> - Driver aborts if usb-role-switch is not added in dt forotg/peripheral >> roles. >> - Added role name strings instead of enum values in debug prints. >> - Updated arguments and variable allignments as per Thierry inputs. >> --- >> V2: >> - Removed dev_set_drvdata for port->dev. >> - Added of_platform_depopulate during error handling and driver removal. >> --- >> drivers/phy/tegra/Kconfig | 1 + >> drivers/phy/tegra/xusb.c | 57 +++++++++++++++++++++++++++++++++++++++++++++++ >> drivers/phy/tegra/xusb.h | 3 +++ >> 3 files changed, 61 insertions(+) >> >> diff --git a/drivers/phy/tegra/Kconfig b/drivers/phy/tegra/Kconfig >> index f9817c3..df07c4d 100644 >> --- a/drivers/phy/tegra/Kconfig >> +++ b/drivers/phy/tegra/Kconfig >> @@ -2,6 +2,7 @@ >> config PHY_TEGRA_XUSB >> tristate "NVIDIA Tegra XUSB pad controller driver" >> depends on ARCH_TEGRA >> + select USB_CONN_GPIO >> help >> Choose this option if you have an NVIDIA Tegra SoC. >> >> diff --git a/drivers/phy/tegra/xusb.c b/drivers/phy/tegra/xusb.c >> index f98ec39..11ea9b5 100644 >> --- a/drivers/phy/tegra/xusb.c >> +++ b/drivers/phy/tegra/xusb.c >> @@ -523,6 +523,7 @@ static int tegra_xusb_port_init(struct tegra_xusb_port *port, >> port->dev.type = &tegra_xusb_port_type; >> port->dev.of_node = of_node_get(np); >> port->dev.parent = padctl->dev; >> + port->dev.driver = padctl->dev->driver; > This looks wrong. I don't think driver's are supposed to set this > because it basically means that the device is being attached to the > driver, but in this case it doesn't get probed by the driver and in > fact the ports don't match the pad controller, so they can't really > be driven by the same driver. > > Is there any particular reason why you need this? > > Thierry Yes, port->dev.driver->owner is accessed in USB role switch driver in API usb_role_switch_get. If driver param is not updated, it causes NULL pointer exception. Based on your inputs, since this assignment is not supposed to used, I believe option available is to create a new device_driver structure and assign the same here. Please share your thoughts. - Nagarjuna