linux/drivers/usb/host/ehci-pci.c
Rene Herman 055b93c9e3 USB: ehci: stop vt6212 bus hogging
The VIA VT6212 defaults to only waiting 1us between passes over EHCI's
async ring, which hammers PCI badly ... and by preventing other devices
from accessing the bus, causes problems like drops in IDE throughput,
a problem that's been bugging users of those chips for several years.

A (partial) datasheet for this chip eventually turned up, letting us
see how to make it use a VIA-specific register to switch over to the
the normal 10us value instead, as suggested by the EHCI specification
Solution noted by Lev A. Melnikovsky.

It's not clear whether this register exists on other VIA chips; we
know that it's ineffective on the vt8235.  So this patch only applies
to chips that seem to be incarnations of the (discrete) vt6212.

Signed-off-by: Rene Herman <rene.herman@gmail.com>
Tested-by: Lev A. Melnikovsky <melnikovsky@mail.ru>
Tested-by: Alessandro Suardi <alessandro.suardi@gmail.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-03-24 22:26:15 -07:00

410 lines
11 KiB
C

/*
* EHCI HCD (Host Controller Driver) PCI Bus Glue.
*
* Copyright (c) 2000-2004 by David Brownell
*
* 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.
*/
#ifndef CONFIG_PCI
#error "This file is PCI bus glue. CONFIG_PCI must be defined."
#endif
/*-------------------------------------------------------------------------*/
/* called after powerup, by probe or system-pm "wakeup" */
static int ehci_pci_reinit(struct ehci_hcd *ehci, struct pci_dev *pdev)
{
u32 temp;
int retval;
/* optional debug port, normally in the first BAR */
temp = pci_find_capability(pdev, 0x0a);
if (temp) {
pci_read_config_dword(pdev, temp, &temp);
temp >>= 16;
if ((temp & (3 << 13)) == (1 << 13)) {
temp &= 0x1fff;
ehci->debug = ehci_to_hcd(ehci)->regs + temp;
temp = ehci_readl(ehci, &ehci->debug->control);
ehci_info(ehci, "debug port %d%s\n",
HCS_DEBUG_PORT(ehci->hcs_params),
(temp & DBGP_ENABLED)
? " IN USE"
: "");
if (!(temp & DBGP_ENABLED))
ehci->debug = NULL;
}
}
/* we expect static quirk code to handle the "extended capabilities"
* (currently just BIOS handoff) allowed starting with EHCI 0.96
*/
/* PCI Memory-Write-Invalidate cycle support is optional (uncommon) */
retval = pci_set_mwi(pdev);
if (!retval)
ehci_dbg(ehci, "MWI active\n");
return 0;
}
/* called during probe() after chip reset completes */
static int ehci_pci_setup(struct usb_hcd *hcd)
{
struct ehci_hcd *ehci = hcd_to_ehci(hcd);
struct pci_dev *pdev = to_pci_dev(hcd->self.controller);
u32 temp;
int retval;
switch (pdev->vendor) {
case PCI_VENDOR_ID_TOSHIBA_2:
/* celleb's companion chip */
if (pdev->device == 0x01b5) {
#ifdef CONFIG_USB_EHCI_BIG_ENDIAN_MMIO
ehci->big_endian_mmio = 1;
#else
ehci_warn(ehci,
"unsupported big endian Toshiba quirk\n");
#endif
}
break;
}
ehci->caps = hcd->regs;
ehci->regs = hcd->regs +
HC_LENGTH(ehci_readl(ehci, &ehci->caps->hc_capbase));
dbg_hcs_params(ehci, "reset");
dbg_hcc_params(ehci, "reset");
/* ehci_init() causes memory for DMA transfers to be
* allocated. Thus, any vendor-specific workarounds based on
* limiting the type of memory used for DMA transfers must
* happen before ehci_init() is called. */
switch (pdev->vendor) {
case PCI_VENDOR_ID_NVIDIA:
/* NVidia reports that certain chips don't handle
* QH, ITD, or SITD addresses above 2GB. (But TD,
* data buffer, and periodic schedule are normal.)
*/
switch (pdev->device) {
case 0x003c: /* MCP04 */
case 0x005b: /* CK804 */
case 0x00d8: /* CK8 */
case 0x00e8: /* CK8S */
if (pci_set_consistent_dma_mask(pdev,
DMA_31BIT_MASK) < 0)
ehci_warn(ehci, "can't enable NVidia "
"workaround for >2GB RAM\n");
break;
}
break;
}
/* cache this readonly data; minimize chip reads */
ehci->hcs_params = ehci_readl(ehci, &ehci->caps->hcs_params);
retval = ehci_halt(ehci);
if (retval)
return retval;
/* data structure init */
retval = ehci_init(hcd);
if (retval)
return retval;
switch (pdev->vendor) {
case PCI_VENDOR_ID_TDI:
if (pdev->device == PCI_DEVICE_ID_TDI_EHCI) {
ehci->is_tdi_rh_tt = 1;
tdi_reset(ehci);
}
break;
case PCI_VENDOR_ID_AMD:
/* AMD8111 EHCI doesn't work, according to AMD errata */
if (pdev->device == 0x7463) {
ehci_info(ehci, "ignoring AMD8111 (errata)\n");
retval = -EIO;
goto done;
}
break;
case PCI_VENDOR_ID_NVIDIA:
switch (pdev->device) {
/* Some NForce2 chips have problems with selective suspend;
* fixed in newer silicon.
*/
case 0x0068:
if (pdev->revision < 0xa4)
ehci->no_selective_suspend = 1;
break;
}
break;
case PCI_VENDOR_ID_VIA:
if (pdev->device == 0x3104 && (pdev->revision & 0xf0) == 0x60) {
u8 tmp;
/* The VT6212 defaults to a 1 usec EHCI sleep time which
* hogs the PCI bus *badly*. Setting bit 5 of 0x4B makes
* that sleep time use the conventional 10 usec.
*/
pci_read_config_byte(pdev, 0x4b, &tmp);
if (tmp & 0x20)
break;
pci_write_config_byte(pdev, 0x4b, tmp | 0x20);
}
break;
}
ehci_reset(ehci);
/* at least the Genesys GL880S needs fixup here */
temp = HCS_N_CC(ehci->hcs_params) * HCS_N_PCC(ehci->hcs_params);
temp &= 0x0f;
if (temp && HCS_N_PORTS(ehci->hcs_params) > temp) {
ehci_dbg(ehci, "bogus port configuration: "
"cc=%d x pcc=%d < ports=%d\n",
HCS_N_CC(ehci->hcs_params),
HCS_N_PCC(ehci->hcs_params),
HCS_N_PORTS(ehci->hcs_params));
switch (pdev->vendor) {
case 0x17a0: /* GENESYS */
/* GL880S: should be PORTS=2 */
temp |= (ehci->hcs_params & ~0xf);
ehci->hcs_params = temp;
break;
case PCI_VENDOR_ID_NVIDIA:
/* NF4: should be PCC=10 */
break;
}
}
/* Serial Bus Release Number is at PCI 0x60 offset */
pci_read_config_byte(pdev, 0x60, &ehci->sbrn);
/* Workaround current PCI init glitch: wakeup bits aren't
* being set from PCI PM capability.
*/
if (!device_can_wakeup(&pdev->dev)) {
u16 port_wake;
pci_read_config_word(pdev, 0x62, &port_wake);
if (port_wake & 0x0001)
device_init_wakeup(&pdev->dev, 1);
}
#ifdef CONFIG_USB_SUSPEND
/* REVISIT: the controller works fine for wakeup iff the root hub
* itself is "globally" suspended, but usbcore currently doesn't
* understand such things.
*
* System suspend currently expects to be able to suspend the entire
* device tree, device-at-a-time. If we failed selective suspend
* reports, system suspend would fail; so the root hub code must claim
* success. That's lying to usbcore, and it matters for for runtime
* PM scenarios with selective suspend and remote wakeup...
*/
if (ehci->no_selective_suspend && device_can_wakeup(&pdev->dev))
ehci_warn(ehci, "selective suspend/wakeup unavailable\n");
#endif
retval = ehci_pci_reinit(ehci, pdev);
done:
return retval;
}
/*-------------------------------------------------------------------------*/
#ifdef CONFIG_PM
/* suspend/resume, section 4.3 */
/* These routines rely on the PCI bus glue
* to handle powerdown and wakeup, and currently also on
* transceivers that don't need any software attention to set up
* the right sort of wakeup.
* Also they depend on separate root hub suspend/resume.
*/
static int ehci_pci_suspend(struct usb_hcd *hcd, pm_message_t message)
{
struct ehci_hcd *ehci = hcd_to_ehci(hcd);
unsigned long flags;
int rc = 0;
if (time_before(jiffies, ehci->next_statechange))
msleep(10);
/* Root hub was already suspended. Disable irq emission and
* mark HW unaccessible, bail out if RH has been resumed. Use
* the spinlock to properly synchronize with possible pending
* RH suspend or resume activity.
*
* This is still racy as hcd->state is manipulated outside of
* any locks =P But that will be a different fix.
*/
spin_lock_irqsave (&ehci->lock, flags);
if (hcd->state != HC_STATE_SUSPENDED) {
rc = -EINVAL;
goto bail;
}
ehci_writel(ehci, 0, &ehci->regs->intr_enable);
(void)ehci_readl(ehci, &ehci->regs->intr_enable);
/* make sure snapshot being resumed re-enumerates everything */
if (message.event == PM_EVENT_PRETHAW) {
ehci_halt(ehci);
ehci_reset(ehci);
}
clear_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
bail:
spin_unlock_irqrestore (&ehci->lock, flags);
// could save FLADJ in case of Vaux power loss
// ... we'd only use it to handle clock skew
return rc;
}
static int ehci_pci_resume(struct usb_hcd *hcd)
{
struct ehci_hcd *ehci = hcd_to_ehci(hcd);
struct pci_dev *pdev = to_pci_dev(hcd->self.controller);
// maybe restore FLADJ
if (time_before(jiffies, ehci->next_statechange))
msleep(100);
/* Mark hardware accessible again as we are out of D3 state by now */
set_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
/* If CF is still set, we maintained PCI Vaux power.
* Just undo the effect of ehci_pci_suspend().
*/
if (ehci_readl(ehci, &ehci->regs->configured_flag) == FLAG_CF) {
int mask = INTR_MASK;
if (!device_may_wakeup(&hcd->self.root_hub->dev))
mask &= ~STS_PCD;
ehci_writel(ehci, mask, &ehci->regs->intr_enable);
ehci_readl(ehci, &ehci->regs->intr_enable);
return 0;
}
ehci_dbg(ehci, "lost power, restarting\n");
usb_root_hub_lost_power(hcd->self.root_hub);
/* Else reset, to cope with power loss or flush-to-storage
* style "resume" having let BIOS kick in during reboot.
*/
(void) ehci_halt(ehci);
(void) ehci_reset(ehci);
(void) ehci_pci_reinit(ehci, pdev);
/* emptying the schedule aborts any urbs */
spin_lock_irq(&ehci->lock);
if (ehci->reclaim)
end_unlink_async(ehci);
ehci_work(ehci);
spin_unlock_irq(&ehci->lock);
ehci_writel(ehci, ehci->command, &ehci->regs->command);
ehci_writel(ehci, FLAG_CF, &ehci->regs->configured_flag);
ehci_readl(ehci, &ehci->regs->command); /* unblock posted writes */
/* here we "know" root ports should always stay powered */
ehci_port_power(ehci, 1);
ehci_handover_companion_ports(ehci);
hcd->state = HC_STATE_SUSPENDED;
return 0;
}
#endif
static const struct hc_driver ehci_pci_hc_driver = {
.description = hcd_name,
.product_desc = "EHCI Host Controller",
.hcd_priv_size = sizeof(struct ehci_hcd),
/*
* generic hardware linkage
*/
.irq = ehci_irq,
.flags = HCD_MEMORY | HCD_USB2,
/*
* basic lifecycle operations
*/
.reset = ehci_pci_setup,
.start = ehci_run,
#ifdef CONFIG_PM
.suspend = ehci_pci_suspend,
.resume = ehci_pci_resume,
#endif
.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,
/*
* scheduling support
*/
.get_frame_number = ehci_get_frame,
/*
* root hub support
*/
.hub_status_data = ehci_hub_status_data,
.hub_control = ehci_hub_control,
.bus_suspend = ehci_bus_suspend,
.bus_resume = ehci_bus_resume,
.relinquish_port = ehci_relinquish_port,
};
/*-------------------------------------------------------------------------*/
/* PCI driver selection metadata; PCI hotplugging uses this */
static const struct pci_device_id pci_ids [] = { {
/* handle any USB 2.0 EHCI controller */
PCI_DEVICE_CLASS(PCI_CLASS_SERIAL_USB_EHCI, ~0),
.driver_data = (unsigned long) &ehci_pci_hc_driver,
},
{ /* end: all zeroes */ }
};
MODULE_DEVICE_TABLE(pci, pci_ids);
/* pci driver glue; this is a "new style" PCI driver module */
static struct pci_driver ehci_pci_driver = {
.name = (char *) hcd_name,
.id_table = pci_ids,
.probe = usb_hcd_pci_probe,
.remove = usb_hcd_pci_remove,
#ifdef CONFIG_PM
.suspend = usb_hcd_pci_suspend,
.resume = usb_hcd_pci_resume,
#endif
.shutdown = usb_hcd_pci_shutdown,
};