[PATCH] ieee1394: ohci1394: flush MMIO writes before delay in initialization

[PATCH] ieee1394: ohci1394: flush MMIO writes before delay in initialization

[Stefan Richter]

and replace busy-wait by msleep.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
---
 drivers/ieee1394/ohci1394.c |   10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

Index: linux/drivers/ieee1394/ohci1394.c
===================================================================
--- linux.orig/drivers/ieee1394/ohci1394.c
+++ linux/drivers/ieee1394/ohci1394.c
@@ -3199,15 +3199,16 @@ static int __devinit ohci1394_pci_probe(
 	/* Now enable LPS, which we need in order to start accessing
 	 * most of the registers.  In fact, on some cards (ALI M5251),
 	 * accessing registers in the SClk domain without LPS enabled
-	 * will lock up the machine.  Wait 50msec to make sure we have
-	 * full link enabled.  */
+	 * will lock up the machine. */
 	reg_write(ohci, OHCI1394_HCControlSet, OHCI1394_HCControl_LPS);
 
 	/* Disable and clear interrupts */
 	reg_write(ohci, OHCI1394_IntEventClear, 0xffffffff);
 	reg_write(ohci, OHCI1394_IntMaskClear, 0xffffffff);
 
-	mdelay(50);
+	/* Flush MMIO writes and wait to make sure we have full link enabled. */
+	reg_read(ohci, OHCI1394_Version);
+	msleep(50);
 
 	/* Determine the number of available IR and IT contexts. */
 	ohci->nb_iso_rcv_ctx =
@@ -3422,7 +3423,8 @@ static int ohci1394_pci_resume(struct pc
 	reg_write(ohci, OHCI1394_HCControlSet, OHCI1394_HCControl_LPS);
 	reg_write(ohci, OHCI1394_IntEventClear, 0xffffffff);
 	reg_write(ohci, OHCI1394_IntMaskClear, 0xffffffff);
-	mdelay(50);
+	reg_read(ohci, OHCI1394_Version);
+	msleep(50);
 
 	err = request_irq(dev->irq, ohci_irq_handler, IRQF_SHARED,
 			  OHCI1394_DRIVER_NAME, ohci);

-- 
Stefan Richter
-=====-==--- ==-- --==-
http://arcgraph.de/sr/