From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Wed, 18 Mar 2015 14:06:27 +0100 (CET) Received: from demumfd002.nsn-inter.net ([93.183.12.31]:35823 "EHLO demumfd002.nsn-inter.net" rhost-flags-OK-OK-OK-OK) by eddie.linux-mips.org with ESMTP id S27007238AbbCRNG0Mlmlu (ORCPT ); Wed, 18 Mar 2015 14:06:26 +0100 Received: from demuprx017.emea.nsn-intra.net ([10.150.129.56]) by demumfd002.nsn-inter.net (8.14.3/8.14.3) with ESMTP id t2ID5Q79032086 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Wed, 18 Mar 2015 13:05:26 GMT Received: from [10.151.38.33] ([10.151.38.33]) by demuprx017.emea.nsn-intra.net (8.12.11.20060308/8.12.11) with ESMTP id t2ID5Lm1011223; Wed, 18 Mar 2015 14:05:21 +0100 Message-ID: <55097811.8050003@nokia.com> Date: Wed, 18 Mar 2015 14:05:21 +0100 From: Alexander Sverdlin User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.1.2 MIME-Version: 1.0 To: Ralf Baechle , linux-mips@linux-mips.org, David Daney , ddaney.cavm@gmail.com, "ext Daney, David" CC: Rob Herring , Jiri Kosina , Randy Dunlap , Masanari Iida , Bjorn Helgaas , "Rulf, Mathias (Nokia - DE/Ulm)" Subject: [PATCH] pci: octeon: Remove udelay() causing huge IRQ latency Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-purgate-type: clean X-purgate-Ad: Categorized by eleven eXpurgate (R) http://www.eleven.de X-purgate: clean X-purgate: This mail is considered clean (visit http://www.eleven.de for further information) X-purgate-size: 2371 X-purgate-ID: 151667::1426683926-00007F9C-137A230F/0/0 Return-Path: X-Envelope-To: <"|/home/ecartis/ecartis -s linux-mips"> (uid 0) X-Orcpt: rfc822;linux-mips@linux-mips.org Original-Recipient: rfc822;linux-mips@linux-mips.org X-archive-position: 46441 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: alexander.sverdlin@nokia.com Precedence: bulk List-help: List-unsubscribe: List-software: Ecartis version 1.0.0 List-Id: linux-mips X-List-ID: linux-mips List-subscribe: List-owner: List-post: List-archive: X-list: linux-mips udelay() in PCI/PCIe read/write callbacks cause 30ms IRQ latency on Octeon platforms because these operations are called from PCI_OP_READ() and PCI_OP_WRITE() under raw_spin_lock_irqsave(). Signed-off-by: Alexander Sverdlin --- arch/mips/include/asm/octeon/pci-octeon.h | 3 --- arch/mips/pci/pci-octeon.c | 6 ------ arch/mips/pci/pcie-octeon.c | 8 -------- 3 files changed, 0 insertions(+), 17 deletions(-) diff --git a/arch/mips/include/asm/octeon/pci-octeon.h b/arch/mips/include/asm/octeon/pci-octeon.h index 64ba56a..1884609 100644 --- a/arch/mips/include/asm/octeon/pci-octeon.h +++ b/arch/mips/include/asm/octeon/pci-octeon.h @@ -11,9 +11,6 @@ #include -/* Some PCI cards require delays when accessing config space. */ -#define PCI_CONFIG_SPACE_DELAY 10000 - /* * The physical memory base mapped by BAR1. 256MB at the end of the * first 4GB. diff --git a/arch/mips/pci/pci-octeon.c b/arch/mips/pci/pci-octeon.c index a04af55..01c604a 100644 --- a/arch/mips/pci/pci-octeon.c +++ b/arch/mips/pci/pci-octeon.c @@ -271,9 +271,6 @@ static int octeon_read_config(struct pci_bus *bus, unsigned int devfn, pci_addr.s.func = devfn & 0x7; pci_addr.s.reg = reg; -#if PCI_CONFIG_SPACE_DELAY - udelay(PCI_CONFIG_SPACE_DELAY); -#endif switch (size) { case 4: *val = le32_to_cpu(cvmx_read64_uint32(pci_addr.u64)); @@ -308,9 +305,6 @@ static int octeon_write_config(struct pci_bus *bus, unsigned int devfn, pci_addr.s.func = devfn & 0x7; pci_addr.s.reg = reg; -#if PCI_CONFIG_SPACE_DELAY - udelay(PCI_CONFIG_SPACE_DELAY); -#endif switch (size) { case 4: cvmx_write64_uint32(pci_addr.u64, cpu_to_le32(val)); diff --git a/arch/mips/pci/pcie-octeon.c b/arch/mips/pci/pcie-octeon.c index 1bb0b2b..99f3db4 100644 --- a/arch/mips/pci/pcie-octeon.c +++ b/arch/mips/pci/pcie-octeon.c @@ -1762,14 +1762,6 @@ static int octeon_pcie_write_config(unsigned int pcie_port, struct pci_bus *bus, default: return PCIBIOS_FUNC_NOT_SUPPORTED; } -#if PCI_CONFIG_SPACE_DELAY - /* - * Delay on writes so that devices have time to come up. Some - * bridges need this to allow time for the secondary busses to - * work - */ - udelay(PCI_CONFIG_SPACE_DELAY); -#endif return PCIBIOS_SUCCESSFUL; }