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[PATCH] USB: UHCI: Increase port-reset completion delay for HP contro…
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…llers

This patch (as657) increases the port-reset completion delay in uhci-hcd
for HP's embedded controllers.  Unlike other UHCI controllers, the HP
chips can take as long as 250 us to carry out the processing associated
with finishing a port reset.

This fixes Novell bug #148761.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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Alan Stern authored and Greg Kroah-Hartman committed Mar 20, 2006
1 parent 491b04c commit ae55717
Showing 1 changed file with 21 additions and 0 deletions.
21 changes: 21 additions & 0 deletions drivers/usb/host/uhci-hub.c
Original file line number Diff line number Diff line change
Expand Up @@ -99,6 +99,21 @@ static void uhci_finish_suspend(struct uhci_hcd *uhci, int port,
}
}

/* Wait for the UHCI controller in HP's iLO2 server management chip.
* It can take up to 250 us to finish a reset and set the CSC bit.
*/
static void wait_for_HP(unsigned long port_addr)
{
int i;

for (i = 10; i < 250; i += 10) {
if (inw(port_addr) & USBPORTSC_CSC)
return;
udelay(10);
}
/* Log a warning? */
}

static void uhci_check_ports(struct uhci_hcd *uhci)
{
unsigned int port;
Expand All @@ -113,6 +128,12 @@ static void uhci_check_ports(struct uhci_hcd *uhci)
CLR_RH_PORTSTAT(USBPORTSC_PR);
udelay(10);

/* HP's server management chip requires
* a longer delay. */
if (to_pci_dev(uhci_dev(uhci))->vendor ==
PCI_VENDOR_ID_HP)
wait_for_HP(port_addr);

/* If the port was enabled before, turning
* reset on caused a port enable change.
* Turning reset off causes a port connect
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