> -----Original Message----- > From: Rob Herring [mailto:robherri...@gmail.com] > Sent: Monday, July 09, 2012 9:58 PM > To: Li Yang-R58472 > Cc: Jia Hongtao-B38951; Greg KH; devicetree-disc...@lists.ozlabs.org; > linux-kernel@vger.kernel.org > Subject: Re: [PATCH V3 5/6] Avoid duplicate probe for of platform devices > > On 07/08/2012 10:46 PM, Li Yang-R58472 wrote: > >>> I don't understand, why is this just showing up now? What > >>> changed to cause this? Couldn't that be the real problem here? > >>> > >> > >> The issue is showing up because we now probe devices twice. > >> Previously, we just probe devices once. But now we changed the way > >> of pci init which makes pci controllers should be probed earlier > >> than other devices. So we have to probe pci nodes separately. Probe > >> more than once is the root cause of this issue. > >> > >> The pci patchset I mentioned please refer to: > >> http://patchwork.ozlabs.org/patch/163742/ > > > > Let me try to clarify a little bit. The of platform bus normally > > traverse the device tree to add all the devices. The change which > > caused problem is that we need to probe PCIe RC devices at a earlier > > stage of initialization. So we added these PCIe RC devices earlier > > than the normal device tree traversal process. These PCIe RC devices > > will be scanned again during the normal traversal and cause > > duplicated devices being added. Our proposal is to deal with > > duplicated devices automatically and make it possible to scan the > > device tree multiple times for devices to be added. > > What is making PCI need to be probed earlier? Perhaps deferred probe > would work?
Pci initialization fsl_add_bridge() should be called earlier as they used to be called in board specific code xx_setup_arch(). Now we put this init part in the probe function of pci controller to make the code infrastructure better. That make pci bus should be probed earlier. > > Perhaps giving of_platform_populate an exclude list of compatible > strings to skip would work. > > Rob Yes, this would work and we actually already implemented this solution. But I think it looks hackish and will influence the other API users. Thanks. -Jia Hongtao. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
