From 4802f16d512d6e3b36177709d50c05df0ef52a6c Mon Sep 17 00:00:00 2001
From: Stefan Richter <stefanr@s5r6.in-berlin.de>
Date: Sun, 21 Feb 2010 17:58:52 +0100
Subject: [PATCH] firewire: ohci: fix IR/IT context mask mixup
This bug was present in firewire-ohci since day one: The number of
available isochronous receive DMA contexts was mixed up with that of
available isochronous transmit DMA contexts.
This is harmless on a few chips which offer the same number of contexts
in both directions, but most chips nowadays implement only the standard
minimum of 4 IR contexts, but 8 IT contexts. If a user attempted to run
a lot of IR contexts at once, results with more than four were therefore
unpredictable. I suppose the controller would simply refuse to start
DMA of any unimplemented context.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
---
drivers/firewire/ohci.c | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)
diff --git a/drivers/firewire/ohci.c b/drivers/firewire/ohci.c
index 9815137b7c7d..a387bcd62466 100644
--- a/drivers/firewire/ohci.c
+++ b/drivers/firewire/ohci.c
@@ -2395,17 +2395,17 @@ static int __devinit pci_probe(struct pci_dev *dev,
OHCI1394_AsRspTrContextControlSet, handle_at_packet);
reg_write(ohci, OHCI1394_IsoRecvIntMaskSet, ~0);
- ohci->it_context_mask = reg_read(ohci, OHCI1394_IsoRecvIntMaskSet);
+ ohci->ir_context_channels = ~0ULL;
+ ohci->ir_context_mask = reg_read(ohci, OHCI1394_IsoRecvIntMaskSet);
reg_write(ohci, OHCI1394_IsoRecvIntMaskClear, ~0);
- size = sizeof(struct iso_context) * hweight32(ohci->it_context_mask);
- ohci->it_context_list = kzalloc(size, GFP_KERNEL);
+ size = sizeof(struct iso_context) * hweight32(ohci->ir_context_mask);
+ ohci->ir_context_list = kzalloc(size, GFP_KERNEL);
reg_write(ohci, OHCI1394_IsoXmitIntMaskSet, ~0);
- ohci->ir_context_channels = ~0ULL;
- ohci->ir_context_mask = reg_read(ohci, OHCI1394_IsoXmitIntMaskSet);
+ ohci->it_context_mask = reg_read(ohci, OHCI1394_IsoXmitIntMaskSet);
reg_write(ohci, OHCI1394_IsoXmitIntMaskClear, ~0);
- size = sizeof(struct iso_context) * hweight32(ohci->ir_context_mask);
- ohci->ir_context_list = kzalloc(size, GFP_KERNEL);
+ size = sizeof(struct iso_context) * hweight32(ohci->it_context_mask);
+ ohci->it_context_list = kzalloc(size, GFP_KERNEL);
if (ohci->it_context_list == NULL || ohci->ir_context_list == NULL) {
err = -ENOMEM;
--
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