Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753082Ab0BUQ7H (ORCPT ); Sun, 21 Feb 2010 11:59:07 -0500 Received: from einhorn.in-berlin.de ([192.109.42.8]:58377 "EHLO einhorn.in-berlin.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753039Ab0BUQ7E (ORCPT ); Sun, 21 Feb 2010 11:59:04 -0500 X-Envelope-From: stefanr@s5r6.in-berlin.de Date: Sun, 21 Feb 2010 17:58:52 +0100 (CET) From: Stefan Richter Subject: [PATCH 7/8] firewire: ohci: fix IR/IT context mask mixup To: linux1394-devel@lists.sourceforge.net cc: linux-kernel@vger.kernel.org In-Reply-To: Message-ID: References: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; CHARSET=us-ascii Content-Disposition: INLINE Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2496 Lines: 56 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 --- drivers/firewire/ohci.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) Index: b/drivers/firewire/ohci.c =================================================================== --- a/drivers/firewire/ohci.c +++ b/drivers/firewire/ohci.c @@ -2395,17 +2395,17 @@ static int __devinit pci_probe(struct pc 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; -- Stefan Richter -=====-==-=- --=- =-=-= http://arcgraph.de/sr/ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/