Revision 6cf11ee6300f38b7cfc43af9b7be2afaa5e05869 authored by Hans Verkuil on 19 January 2015, 09:16:18 UTC, committed by Mauro Carvalho Chehab on 21 January 2015, 23:07:26 UTC
The locking scheme inside the vb2 thread is unsafe when stopping the thread. In particular kthread_stop was called *after* internal data structures were cleaned up instead of doing that before. In addition, internal vb2 functions were called after threadio->stop was set to true and vb2_internal_streamoff was called. This is also not allowed. All this led to a variety of race conditions and kernel warnings and/or oopses. Fixed by moving the kthread_stop call up before the cleanup takes place, and by checking threadio->stop before calling internal vb2 queuing operations. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Cc: <stable@vger.kernel.org> # for v3.16 and up Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
1 parent 42d74e4
ehci-xilinx-of.c
/*
* EHCI HCD (Host Controller Driver) for USB.
*
* Bus Glue for Xilinx EHCI core on the of_platform bus
*
* Copyright (c) 2009 Xilinx, Inc.
*
* Based on "ehci-ppc-of.c" by Valentine Barshak <vbarshak@ru.mvista.com>
* and "ehci-ppc-soc.c" by Stefan Roese <sr@denx.de>
* and "ohci-ppc-of.c" by Sylvain Munaut <tnt@246tNt.com>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software Foundation,
* Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
*/
#include <linux/err.h>
#include <linux/signal.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
/**
* ehci_xilinx_port_handed_over - hand the port out if failed to enable it
* @hcd: Pointer to the usb_hcd device to which the host controller bound
* @portnum:Port number to which the device is attached.
*
* This function is used as a place to tell the user that the Xilinx USB host
* controller does support LS devices. And in an HS only configuration, it
* does not support FS devices either. It is hoped that this can help a
* confused user.
*
* There are cases when the host controller fails to enable the port due to,
* for example, insufficient power that can be supplied to the device from
* the USB bus. In those cases, the messages printed here are not helpful.
*/
static int ehci_xilinx_port_handed_over(struct usb_hcd *hcd, int portnum)
{
dev_warn(hcd->self.controller, "port %d cannot be enabled\n", portnum);
if (hcd->has_tt) {
dev_warn(hcd->self.controller,
"Maybe you have connected a low speed device?\n");
dev_warn(hcd->self.controller,
"We do not support low speed devices\n");
} else {
dev_warn(hcd->self.controller,
"Maybe your device is not a high speed device?\n");
dev_warn(hcd->self.controller,
"The USB host controller does not support full speed "
"nor low speed devices\n");
dev_warn(hcd->self.controller,
"You can reconfigure the host controller to have "
"full speed support\n");
}
return 0;
}
static const struct hc_driver ehci_xilinx_of_hc_driver = {
.description = hcd_name,
.product_desc = "OF EHCI",
.hcd_priv_size = sizeof(struct ehci_hcd),
/*
* generic hardware linkage
*/
.irq = ehci_irq,
.flags = HCD_MEMORY | HCD_USB2 | HCD_BH,
/*
* basic lifecycle operations
*/
.reset = ehci_setup,
.start = ehci_run,
.stop = ehci_stop,
.shutdown = ehci_shutdown,
/*
* managing i/o requests and associated device resources
*/
.urb_enqueue = ehci_urb_enqueue,
.urb_dequeue = ehci_urb_dequeue,
.endpoint_disable = ehci_endpoint_disable,
.endpoint_reset = ehci_endpoint_reset,
/*
* scheduling support
*/
.get_frame_number = ehci_get_frame,
/*
* root hub support
*/
.hub_status_data = ehci_hub_status_data,
.hub_control = ehci_hub_control,
#ifdef CONFIG_PM
.bus_suspend = ehci_bus_suspend,
.bus_resume = ehci_bus_resume,
#endif
.relinquish_port = NULL,
.port_handed_over = ehci_xilinx_port_handed_over,
.clear_tt_buffer_complete = ehci_clear_tt_buffer_complete,
};
/**
* ehci_hcd_xilinx_of_probe - Probe method for the USB host controller
* @op: pointer to the platform_device bound to the host controller
*
* This function requests resources and sets up appropriate properties for the
* host controller. Because the Xilinx USB host controller can be configured
* as HS only or HS/FS only, it checks the configuration in the device tree
* entry, and sets an appropriate value for hcd->has_tt.
*/
static int ehci_hcd_xilinx_of_probe(struct platform_device *op)
{
struct device_node *dn = op->dev.of_node;
struct usb_hcd *hcd;
struct ehci_hcd *ehci;
struct resource res;
int irq;
int rv;
int *value;
if (usb_disabled())
return -ENODEV;
dev_dbg(&op->dev, "initializing XILINX-OF USB Controller\n");
rv = of_address_to_resource(dn, 0, &res);
if (rv)
return rv;
hcd = usb_create_hcd(&ehci_xilinx_of_hc_driver, &op->dev,
"XILINX-OF USB");
if (!hcd)
return -ENOMEM;
hcd->rsrc_start = res.start;
hcd->rsrc_len = resource_size(&res);
irq = irq_of_parse_and_map(dn, 0);
if (!irq) {
dev_err(&op->dev, "%s: irq_of_parse_and_map failed\n",
__FILE__);
rv = -EBUSY;
goto err_irq;
}
hcd->regs = devm_ioremap_resource(&op->dev, &res);
if (IS_ERR(hcd->regs)) {
rv = PTR_ERR(hcd->regs);
goto err_irq;
}
ehci = hcd_to_ehci(hcd);
/* This core always has big-endian register interface and uses
* big-endian memory descriptors.
*/
ehci->big_endian_mmio = 1;
ehci->big_endian_desc = 1;
/* Check whether the FS support option is selected in the hardware.
*/
value = (int *)of_get_property(dn, "xlnx,support-usb-fs", NULL);
if (value && (*value == 1)) {
ehci_dbg(ehci, "USB host controller supports FS devices\n");
hcd->has_tt = 1;
} else {
ehci_dbg(ehci,
"USB host controller is HS only\n");
hcd->has_tt = 0;
}
/* Debug registers are at the first 0x100 region
*/
ehci->caps = hcd->regs + 0x100;
rv = usb_add_hcd(hcd, irq, 0);
if (rv == 0) {
device_wakeup_enable(hcd->self.controller);
return 0;
}
err_irq:
usb_put_hcd(hcd);
return rv;
}
/**
* ehci_hcd_xilinx_of_remove - shutdown hcd and release resources
* @op: pointer to platform_device structure that is to be removed
*
* Remove the hcd structure, and release resources that has been requested
* during probe.
*/
static int ehci_hcd_xilinx_of_remove(struct platform_device *op)
{
struct usb_hcd *hcd = platform_get_drvdata(op);
dev_dbg(&op->dev, "stopping XILINX-OF USB Controller\n");
usb_remove_hcd(hcd);
usb_put_hcd(hcd);
return 0;
}
static const struct of_device_id ehci_hcd_xilinx_of_match[] = {
{.compatible = "xlnx,xps-usb-host-1.00.a",},
{},
};
MODULE_DEVICE_TABLE(of, ehci_hcd_xilinx_of_match);
static struct platform_driver ehci_hcd_xilinx_of_driver = {
.probe = ehci_hcd_xilinx_of_probe,
.remove = ehci_hcd_xilinx_of_remove,
.shutdown = usb_hcd_platform_shutdown,
.driver = {
.name = "xilinx-of-ehci",
.owner = THIS_MODULE,
.of_match_table = ehci_hcd_xilinx_of_match,
},
};
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