On Wednesday 07 October 2015 18:08:47 Bjorn Helgaas wrote: > [+cc Matthew] > > On Wed, Oct 07, 2015 at 01:08:40PM -0700, David Daney wrote: > > On 10/07/2015 12:44 PM, Bjorn Helgaas wrote: > > >Hi David, > > > > > >On Fri, Oct 02, 2015 at 11:43:59AM -0700, David Daney wrote: > > >>From: David Daney <david.daney@xxxxxxxxxx> > > >> > > >>pci_bus_fixup_irqs() works like pci_fixup_irqs(), except it only does > > >>the fixups for devices on the specified bus. > > >> > > >>Follow-on patch will use the new function. > > >> > > >>Signed-off-by: David Daney <david.daney@xxxxxxxxxx> > > >>--- > > >>No change from v2. > > >> > > >> drivers/pci/setup-irq.c | 30 ++++++++++++++++++++++++++++++ > > >> include/linux/pci.h | 4 ++++ > > >> 2 files changed, 34 insertions(+) > > >> > > >>diff --git a/drivers/pci/setup-irq.c b/drivers/pci/setup-irq.c > > >>index 95c225b..189ad17 100644 > > >>--- a/drivers/pci/setup-irq.c > > >>+++ b/drivers/pci/setup-irq.c > > >>@@ -66,3 +66,33 @@ void pci_fixup_irqs(u8 (*swizzle)(struct pci_dev *, > > >>u8 *),> >> > > >> pdev_fixup_irq(dev, swizzle, map_irq); > > >> > > >> } > > >> EXPORT_SYMBOL_GPL(pci_fixup_irqs); > > >> > > >>+ > > >>+struct pci_bus_fixup_cb_info { > > >>+ u8 (*swizzle)(struct pci_dev *, u8 *); > > >>+ int (*map_irq)(const struct pci_dev *, u8, u8); > > >>+}; > > >>+ > > >>+static int pci_bus_fixup_irq_cb(struct pci_dev *dev, void *arg) > > >>+{ > > >>+ struct pci_bus_fixup_cb_info *info = arg; > > >>+ > > >>+ pdev_fixup_irq(dev, info->swizzle, info->map_irq); > > >>+ return 0; > > >>+} > > >>+ > > >>+/* > > >>+ * Fixup the irqs only for devices on the given bus using supplied > > >>+ * swizzle and map_irq function pointers > > >>+ */ > > >>+void pci_bus_fixup_irqs(struct pci_bus *bus, > > >>+ u8 (*swizzle)(struct pci_dev *, u8 *), > > >>+ int (*map_irq)(const struct pci_dev *, u8, u8)) > > >>+{ > > >>+ struct pci_bus_fixup_cb_info info; > > >>+ > > >>+ info.swizzle = swizzle; > > >>+ info.map_irq = map_irq; > > >>+ pci_walk_bus(bus, pci_bus_fixup_irq_cb, &info); > > > > > >I don't like the existing pci_fixup_irqs(), so by transitivity, I > > >don't like pci_bus_fixup_irqs() either. > > > > We are in agreement with respect to this point. > > > > > The problem is that in both > > > > > >cases this is a one-time pass over the tree, so we don't handle > > >hot-added devices correctly. > > > > > >I think we need to get rid of pci_fixup_irqs() and somehow integrate > > >it into the pci_device_add() path, where it would be done once for > > >every device we enumerate. > > > > I also agree with this point. > > > > > If we did that, I don't think you would > > > > > >need to add pci_bus_fixup_irqs(), would you? > > > > Nope. > > > > However, such a change is essentially untestable by me. So, I > > didn't attempt it. pci_fixup_irqs() is used by alpha, arm, m68k, > > mips, sh, sparc, tile, unicore32 and other things as well. If the > > core pci_device_add() code were to suddenly start doing the fixup, > > there would be the potential to break all these things I cannot > > test. > > Yep, that's certainly a risk. I can't test all those arches either, > but I think it's a risk worth taking because the end result is more > maintainable. > > Matthew Minter did some really nice work on this last year, but it got > stalled somehow. I wonder if we can resurrect it? It seems like it > was pretty close to being ready. Here's a pointer to the last posting > I saw: > > http://lkml.kernel.org/r/1412222866-21068-1-git-send-email-matt@xxxxxxxxxxxx > > Bjorn Thanks for adding me into the loop, Yes, I had been working on this last year, and got a patchset that was tested on arm, x86 (and amd64), and slightly tested on powerpc. However I was not able to test other architectures as they were not available in the software lab I work in but should in theory work on all arches the kernel runs on. I can say that that patchset is being used by several projects out of tree currently but unfortunately due to a shift in priorities in the lab I was working for I lost access to the resources to develop and test the patch easily. I have done some additional work personally on it but so far have not got anything that I am happy to submit for inclusion in tree. (due to a number of issues in structure and a complication relating to weak functions where multiple variations of the same arch exist. You can see in thread that is linked above (http://lkml.kernel.org/r/1412222866-21068-1-git-send-email-matt@xxxxxxxxxxxx) some feedback on the issues that need to be solved. I also expect that the patchset needs to be pulled forward to a newer kernel as I have been working in a frozen tree without rebasing to reduce test complexity. I would be happy to put some time this weekend if possible into reviewing the state of this and seeing if I can at least put together a version running on a recent kernel. I can also go over the issues again which were proving problematic and see if any of them are easy to fix. However I can only work on this in my own time for now and on my own boxes (which are all x86 and amd64) so the amount I can do will be limited. However any assistance in fixing the issues would be appreciated, I will try and throw up a git repo somewhere this weekend with the latest patches if anyone is able to take a look. In the mean time, the biggest issues with the current iteration and the full thread are here: http://comments.gmane.org/gmane.linux.kernel.pci/35756 I will get a repo somewhere online for browsing soon but cannot quite yet as I need to clean up the repo a little first. Kind regards to all, Matthew Minter -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html