On 2023/7/28 21:39, Will Deacon wrote: > On Thu, Jul 27, 2023 at 11:45:22AM +0800, Shuai Xue wrote: >> >> >> On 2023/7/26 04:59, Bjorn Helgaas wrote: >>> On Mon, Jul 24, 2023 at 10:18:07AM +0100, Jonathan Cameron wrote: >>>> On Mon, 24 Jul 2023 10:34:08 +0800 >>>> Shuai Xue <xueshuai@xxxxxxxxxxxxxxxxx> wrote: >>>>> On 2023/7/10 20:04, Shuai Xue wrote: >>>>>> On 2023/6/16 16:39, Shuai Xue wrote: >>>>>>> On 2023/6/6 15:49, Shuai Xue wrote: >>> >>>>>>>> This patchset adds the PCIe Performance Monitoring Unit (PMU) driver support >>>>>>>> for T-Head Yitian 710 SoC chip. Yitian 710 is based on the Synopsys PCI Express >>>>>>>> Core controller IP which provides statistics feature. >>> >>>> ... >>>> Really a question for Bjorn I think, but here is my 2 cents... >>>> >>>> The problem here is that we need to do that fundamental redesign of the >>>> way the PCI ports drivers work. I'm not sure there is a path to merging >>>> this until that is done. The bigger problem is that I'm not sure anyone >>>> is actively looking at that yet. I'd like to look at this (as I have >>>> the same problem for some other drivers), but it is behind various >>>> other things on my todo list. >>>> >>>> Bjorn might be persuaded on a temporary solution, but that would come >>>> with some maintenance problems, particularly when we try to do it >>>> 'right' in the future. Maybe adding another service driver would be >>>> a stop gap as long as we know we won't keep doing so for ever. Not sure. >>> >>> I think the question here is around the for_each_pci_dev() in >>> __dwc_pcie_pmu_probe()? I don't *like* that because of the >>> assumptions it breaks (autoload doesn't work, hotplug doesn't work), >>> but: >>> >>> - There are several other drivers that also do this, >>> - I don't have a better suggest for any of them, >>> - It's not a drivers/pci thing, so not really up to me anyway, >>> >>> so I don't have any problem with this being merged as-is, as long as >>> you can live with the limitations. >>> >>> I don't think this series does anything to work around those >>> limitations, i.e., it doesn't make up fake device IDs for module >>> loading or fake events for hotplug, so it seems like we could improve >>> the implementation later if we ever have a way to do it. >>> >>> Bjorn >> >> + Will >> >> Ok, thank you for confirmation, Bjorn. Then it comes to perf driver parts and >> it is really a question for @Will I think. >> >> What's your opinion about merging this patch set, @Will? > > No fundamental objection from me, but I'll have a closer look when you > post a version addressing the feedback from Jonathan and Yicong. Thanks for your input! I appreciate that you don't have any fundamental objections to merging the patch set. I'll definitely take into account the feedback from Jonathan and Yicong before posting a revised version. Best Regards, Cheers. Shuai
