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authorAlan Stern <stern@rowland.harvard.edu>2011-11-17 16:41:45 -0500
committerGreg Kroah-Hartman <gregkh@suse.de>2011-11-18 11:18:45 -0800
commitc61875977458637226ab093a35d200f2d5789787 (patch)
tree8599601ac6abc0532f11858d572119d260d9925c /drivers/usb/host/ohci-hcd.c
parent46b5a277ed90317a4d17e936c16037e76011b219 (diff)
OHCI: final fix for NVIDIA problems (I hope)
Problems with NVIDIA's OHCI host controllers persist. After looking carefully through the spec, I finally realized that when a controller is reset it then automatically goes into a SUSPEND state in which it is completely quiescent (no DMA and no IRQs) and from which it will not awaken until the system puts it into the OPERATIONAL state. Therefore there's no need to worry about controllers being in the RESET state for extended periods, or remaining in the OPERATIONAL state during system shutdown. The proper action for device initialization is to put the controller into the RESET state (if it's not there already) and then to issue a software reset. Similarly, the proper action for device shutdown is simply to do a software reset. This patch (as1499) implements such an approach. It simplifies initialization and shutdown, and allows the NVIDIA shutdown-quirk code to be removed. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Tested-by: Andre "Osku" Schmidt <andre.osku.schmidt@googlemail.com> Tested-by: Arno Augustin <Arno.Augustin@web.de> Cc: stable <stable@vger.kernel.org> [after tested in 3.2 for a while] Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/usb/host/ohci-hcd.c')
-rw-r--r--drivers/usb/host/ohci-hcd.c15
1 files changed, 6 insertions, 9 deletions
diff --git a/drivers/usb/host/ohci-hcd.c b/drivers/usb/host/ohci-hcd.c
index 34efd479e068..b2639191549e 100644
--- a/drivers/usb/host/ohci-hcd.c
+++ b/drivers/usb/host/ohci-hcd.c
@@ -389,17 +389,14 @@ ohci_shutdown (struct usb_hcd *hcd)
struct ohci_hcd *ohci;
ohci = hcd_to_ohci (hcd);
- ohci_writel (ohci, OHCI_INTR_MIE, &ohci->regs->intrdisable);
- ohci->hc_control = ohci_readl(ohci, &ohci->regs->control);
+ ohci_writel(ohci, (u32) ~0, &ohci->regs->intrdisable);
- /* If the SHUTDOWN quirk is set, don't put the controller in RESET */
- ohci->hc_control &= (ohci->flags & OHCI_QUIRK_SHUTDOWN ?
- OHCI_CTRL_RWC | OHCI_CTRL_HCFS :
- OHCI_CTRL_RWC);
- ohci_writel(ohci, ohci->hc_control, &ohci->regs->control);
+ /* Software reset, after which the controller goes into SUSPEND */
+ ohci_writel(ohci, OHCI_HCR, &ohci->regs->cmdstatus);
+ ohci_readl(ohci, &ohci->regs->cmdstatus); /* flush the writes */
+ udelay(10);
- /* flush the writes */
- (void) ohci_readl (ohci, &ohci->regs->control);
+ ohci_writel(ohci, ohci->fminterval, &ohci->regs->fminterval);
}
static int check_ed(struct ohci_hcd *ohci, struct ed *ed)