From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yinghai Lu Subject: Re: [PATCH] pci, e1000e: Add and use __pci_disable_link_state Date: Wed, 11 May 2011 13:23:21 -0700 Message-ID: <4DCAF039.4030207@kernel.org> References: <4DC6E6E8.9040306@kernel.org> <20110509143536.08bd0297@jbarnes-desktop> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: Andrew Morton , Naga Chumbalkar , e1000-devel@lists.sourceforge.net, Bruce Allan , Jesse Brandeburg , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, "Rafael J. Wysocki" , John Ronciak , Kenji Kaneshige , netdev@vger.kernel.org, Matthew Garrett To: Jesse Barnes Return-path: In-Reply-To: <20110509143536.08bd0297@jbarnes-desktop> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: e1000-devel-bounces@lists.sourceforge.net List-Id: netdev.vger.kernel.org On 05/09/2011 02:35 PM, Jesse Barnes wrote: > On Sun, 08 May 2011 11:54:32 -0700 > Yinghai Lu wrote: > >> >> Need to use it in _e1000e_disable_aspm. >> when aer happens, >> pci_walk_bus already have down_read(&pci_bus_sem)... >> then report_slot_reset >> ==> e1000_io_slot_reset >> ==> e1000e_disable_aspm >> ==> pci_disable_link_state... >> >> We can not use pci_disable_link_state, and it will try to hold pci_bus_sem again. >> >> Try to have __pci_disable_link_state that will not need to hold pci_bus_sem. > > What about the other callers of e1000e_disable_aspm? Do they already > have the lock held or is it just reset that needs the already locked > version? yes. there is another version when aspm is not defined. and it does not use any lock. #ifdef CONFIG_PCIEASPM static void __e1000e_disable_aspm(struct pci_dev *pdev, u16 state) { pci_disable_link_state(pdev, state); } #else static void __e1000e_disable_aspm(struct pci_dev *pdev, u16 state) { int pos; u16 reg16; /* * Both device and parent should have the same ASPM setting. * Disable ASPM in downstream component first and then upstream. */ pos = pci_pcie_cap(pdev); pci_read_config_word(pdev, pos + PCI_EXP_LNKCTL, ®16); reg16 &= ~state; pci_write_config_word(pdev, pos + PCI_EXP_LNKCTL, reg16); if (!pdev->bus->self) return; pos = pci_pcie_cap(pdev->bus->self); pci_read_config_word(pdev->bus->self, pos + PCI_EXP_LNKCTL, ®16); reg16 &= ~state; pci_write_config_word(pdev->bus->self, pos + PCI_EXP_LNKCTL, reg16); } #endif > >> +extern void __pci_disable_link_state(struct pci_dev *pdev, int state); >> extern void pcie_clear_aspm(void); >> extern void pcie_no_aspm(void); >> #else > > pci_disable_link_state_locked would be more descriptive and would match > other usage in the kernel. ok. Thanks Yinghai ------------------------------------------------------------------------------ Achieve unprecedented app performance and reliability What every C/C++ and Fortran developer should know. Learn how Intel has extended the reach of its next-generation tools to help boost performance applications - inlcuding clusters. http://p.sf.net/sfu/intel-dev2devmay _______________________________________________ E1000-devel mailing list E1000-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/e1000-devel To learn more about Intel® Ethernet, visit http://communities.intel.com/community/wired