From mboxrd@z Thu Jan 1 00:00:00 1970 From: l.stach@pengutronix.de (Lucas Stach) Date: Fri, 28 Feb 2014 17:55:43 +0100 Subject: [RFC PATCH 0/3] PCI: imx6: fixup for add-in card IRQ mismapping In-Reply-To: References: <1393550394-11071-1-git-send-email-tharvey@gateworks.com> <000701cf3427$72f1c590$58d550b0$%han@samsung.com> <000001cf344d$845edf90$8d1c9eb0$%han@samsung.com> Message-ID: <1393606543.5225.15.camel@weser.hi.pengutronix.de> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Am Freitag, den 28.02.2014, 08:52 -0800 schrieb Tim Harvey: > On Thu, Feb 27, 2014 at 10:22 PM, Jingoo Han wrote: > > On Friday, February 28, 2014 1:16 PM, Tim Harvey wrote: > >> On Thu, Feb 27, 2014 at 5:50 PM, Jingoo Han wrote: > >> > > >> > On Friday, February 28, 2014 10:20 AM, Tim Harvey wrote: > >> > > > >> > > An add-in card used on the Ventana IMX6 SoC based family of boards has a > >> > > TI XIO2001 PCIe-to-PCI bridge where the INTA/B/C/D mappings between the > >> > > bridge and the four mini-PCI slots are swapped (INTD/C/B/A). > >> > > >> > (+cc Marek Vasut, Pratyush Anand, Kishon Vijay Abraham I, Mohit KUMAR DCG) > >> > > >> > This problem happens from the 'Board', not a 'SoC'. > >> > 'TI XIO2001 PCIe-to-PCI bridge' is not a 'SoC'. > >> > 'pci-imx6.c' is the driver for 'IMX6 PCI IP', not for 'IMX6 SoC based > >> > board'. Isn't it? > >> > >> Jingoo, > >> > >> Correct, this is an issue in the way the XIO2001 was hooked up to the > >> PCI slots, so it should be viewed as a board issue. > > > > (+CC Arnd Bergmann) > > > > Then, this board fixup code should NOT be placed in './drivers/pci/host/' > > side. > > > >> > >> > > >> > Then, the workaround code for board problem should NOT be > >> > included to './drivers/pci/host/' side. > >> > >> I would agree, but to overcome this sort of interrupt mapping issue > >> one would need to either implement a custom swizzle or perhaps a > >> custom map_irq and both of those are hooked into the pcie driver core. > >> Do you have any suggestions on where/how I would better hook into > >> those? > > > > Anyway, 'TI XIO2001 PCIe-to-PCI bridge' chip on the board is the > > culprit. So, the board specific side is a good place. > > For instance, ./arch/arm/mach-imx/ > > > > I don't know how to handle this problem. > > But, there is no reason that 'pcie-designware.c' should take a care > > of the board specific issue. > > > > Arnd Bergmann, > > Would you give your opinions? > > I agree with what your saying, but I don't see a way to put a custom > map_irq or swizzle in arch/arm/mach-imx when the imx6 pcie driver is > in drivers/pci/host. Many machines sitll have their pcie host > controller drivers in arch/arm/mach-* but the imx6 was placed in > drivers/host/pci because it shares the designware core with other > boards (exynos if not more). > > If you look at the PATCH 3/3, I did take care to work around this in > pci-imx6.c 'not' pcie-designware.c (I had to add support for assigning > a custom swizzle - see PATH 2/3). > > I'm looking for suggestions as to if/how to get it into someplace more > 'board-specific' (arch/arm/mach-imx) or 'device-specific' (ie pci > fixup for xio2001). As far as I can tell this has to be resolved with > either a custom swizzle or map_irq which are function pointers in > struct hw_pci which is passed in to pci_common_init from pci host > controller drivers. > > Perhaps there is a way to re-assign the swizzle function after > pcie-designware.c has called pci_common_init? I see that > pcibios_init_hw assignes the map_irq/swizzle passed in from the struct > hw_pci to a struct pci_sys_data yet I'm not sure if I can get to this > structure within a pci fixup. > I'll send a series to fix the IRQ mapping in the host driver in a few minutes. After this you should be able to trivially represent you swizzled IRQ lines by adding your PCIe-to-PCI bridge in the devicetree of your board and set the correct IRQ mapping table. Regards, Lucas -- Pengutronix e.K. | Lucas Stach | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-5076 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |