Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934499Ab3CZOWr (ORCPT ); Tue, 26 Mar 2013 10:22:47 -0400 Received: from mailout02.c08.mtsvc.net ([205.186.168.190]:35497 "EHLO mailout02.c08.mtsvc.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933449Ab3CZOWq (ORCPT ); Tue, 26 Mar 2013 10:22:46 -0400 From: Peter Hurley To: Stefan Richter Cc: linux1394-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org, Peter Hurley Subject: [PATCH] firewire: Enable physical DMA above 4GB Date: Tue, 26 Mar 2013 10:22:14 -0400 Message-Id: <1364307734-27709-1-git-send-email-peter@hurleysoftware.com> X-Mailer: git-send-email 1.8.1.2 X-Authenticated-User: 125194 peter@hurleysoftware.com Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1627 Lines: 45 Quadlet reads to memory above 4GB is painfully slow when serviced by the AR DMA context. In addition, the CPU(s) may be locked-up, preventing any transfer at all. Write the PhyUpperBound register with the end-of-memory value. If end-of-memory is beyond the OHCI limit of 0x0000ffff00000000, clamp to that value. Signed-off-by: Peter Hurley --- drivers/firewire/ohci.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/firewire/ohci.c b/drivers/firewire/ohci.c index 044ace3..b4135a5 100644 --- a/drivers/firewire/ohci.c +++ b/drivers/firewire/ohci.c @@ -2249,6 +2249,7 @@ static int ohci_enable(struct fw_card *card, struct pci_dev *dev = to_pci_dev(card->device); u32 lps, version, irqs; int i, ret; + u32 phys_upper; if (software_reset(ohci)) { dev_err(card->device, "failed to reset ohci card\n"); @@ -2323,7 +2324,10 @@ static int ohci_enable(struct fw_card *card, reg_write(ohci, OHCI1394_FairnessControl, 0); card->priority_budget_implemented = ohci->pri_req_max != 0; - reg_write(ohci, OHCI1394_PhyUpperBound, 0x00010000); + phys_upper = min(0xffff0000ULL, + (dma_get_required_mask(card->device) >> 16) + 1); + reg_write(ohci, OHCI1394_PhyUpperBound, max(phys_upper, 0x00010000U)); + reg_write(ohci, OHCI1394_IntEventClear, ~0); reg_write(ohci, OHCI1394_IntMaskClear, ~0); -- 1.8.1.2 -- 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/