| From | Ben Hutchings <> | Date | Tue, 05 May 2015 02:16:39 +0100 | Subject | [PATCH 3.2 023/221] USB: add flag for HCDs that can't receive wakeup requests (isp1760-hcd) |
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3.2.69-rc1 review patch. If anyone has any objections, please let me know.
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From: Alan Stern <stern@rowland.harvard.edu>
commit 074f9dd55f9cab1b82690ed7e44bcf38b9616ce0 upstream.
Currently the USB stack assumes that all host controller drivers are capable of receiving wakeup requests from downstream devices. However, this isn't true for the isp1760-hcd driver, which means that it isn't safe to do a runtime suspend of any device attached to a root-hub port if the device requires wakeup.
This patch adds a "cant_recv_wakeups" flag to the usb_hcd structure and sets the flag in isp1760-hcd. The core is modified to prevent a direct child of the root hub from being put into runtime suspend with wakeup enabled if the flag is set.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Tested-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Greg Kroah-Hartman <greg@kroah.com> [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> --- drivers/usb/core/driver.c | 12 ++++++++++++ drivers/usb/host/isp1760-hcd.c | 3 +++ include/linux/usb/hcd.h | 2 ++ 3 files changed, 17 insertions(+)
--- a/drivers/usb/core/driver.c +++ b/drivers/usb/core/driver.c @@ -1664,6 +1664,18 @@ static int autosuspend_check(struct usb_ dev_dbg(&udev->dev, "remote wakeup needed for autosuspend\n"); return -EOPNOTSUPP; } + + /* + * If the device is a direct child of the root hub and the HCD + * doesn't handle wakeup requests, don't allow autosuspend when + * wakeup is needed. + */ + if (w && udev->parent == udev->bus->root_hub && + bus_to_hcd(udev->bus)->cant_recv_wakeups) { + dev_dbg(&udev->dev, "HCD doesn't handle wakeup requests\n"); + return -EOPNOTSUPP; + } + udev->do_remote_wakeup = w; return 0; } --- a/drivers/usb/host/isp1760-hcd.c +++ b/drivers/usb/host/isp1760-hcd.c @@ -2254,6 +2254,9 @@ struct usb_hcd *isp1760_register(phys_ad hcd->rsrc_start = res_start; hcd->rsrc_len = res_len; + /* This driver doesn't support wakeup requests */ + hcd->cant_recv_wakeups = 1; + ret = usb_add_hcd(hcd, irq, irqflags); if (ret) goto err_unmap; --- a/include/linux/usb/hcd.h +++ b/include/linux/usb/hcd.h @@ -128,6 +128,8 @@ struct usb_hcd { unsigned wireless:1; /* Wireless USB HCD */ unsigned authorized_default:1; unsigned has_tt:1; /* Integrated TT in root hub */ + unsigned cant_recv_wakeups:1; + /* wakeup requests from downstream aren't received */ int irq; /* irq allocated */ void __iomem *regs; /* device memory/io */
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