From mboxrd@z Thu Jan 1 00:00:00 1970 From: marc.zyngier@arm.com (Marc Zyngier) Date: Thu, 06 Aug 2015 17:53:50 +0100 Subject: [PATCH v5 9/9] PCI: xgene: Use pci_scan_root_bus_msi() In-Reply-To: References: <20150804214234.9189.42548.stgit@bhelgaas-glaptop2.roam.corp.google.com> <20150804215457.9189.27595.stgit@bhelgaas-glaptop2.roam.corp.google.com> <55C37C92.1020509@arm.com> Message-ID: <55C3911E.9090907@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 06/08/15 17:41, Ley Foon Tan wrote: > On Thu, Aug 6, 2015 at 11:26 PM, Marc Zyngier wrote: >> Hi Bjorn, >> >> On 04/08/15 22:54, Bjorn Helgaas wrote: >>> Previously there was no way to specify the MSI controller when creating a >>> new PCI root bus, so we had to create the bus, set its MSI controller, then >>> scan the bus. With the new pci_scan_root_bus_msi() interface, we can >>> specify the MSI controller up front and get rid of that intermediate step. >>> >>> Look up the MSI controller first, then use pci_scan_root_bus_msi() to >>> create and scan the root PCI bus. >> >> I'm wondering about these XGene patches. >> >> With the code that is queued for v4.3 in tip/irq/core, the X-Gene MSI >> driver doesn't export a struct msi_controller anymore, and entirely >> relies on IRQ domains to identify to be matched with the actual PCI driver. >> >> Do you intend this as a cleanup until everything lands in mainline? At >> that point, we'd be able to remove all traces of struct msi_controller >> from this driver. >> >> Alternatively, we could ask tglx to add an extra patch to the existing >> queue in order to clean up pci-xgene.c (nuking the whole >> xgene_pcie_msi_enable function). >> >> Thoughts? > > In pcie-altera driver, it uses pci_scan_root_bus() and it doesn't call > to of_pci_find_msi_chip_by_node() to retrieve msi_controller struct as > well. > But, the msi domain stuff is still working. Should I change it to > pci_scan_root_bus_msi()? If you're not using struct msi_controller, I don't see a reason to use pci_scan_root_bus_msi(). The MSI irq domain patches are queued for 4.3, and I don't believe your driver will be merged before that. Eventually, I'd like to kill msi_controller entirely. It is completely redundant with the use of irq domains. Thanks, M. -- Jazz is not dead. It just smells funny...