Re: [Bug 219513] New: PCIe drivers do not bind

[Dullfire <dullfire@yahoo.com>]

On 11/19/24 08:04, Bjorn Helgaas wrote:
> On Tue, Nov 19, 2024 at 12:55:36PM +0000, bugzilla-daemon@kernel.org wrote:
>> https://bugzilla.kernel.org/show_bug.cgi?id=219513
>>
>>           Hardware: Sparc64
>>           Priority: P3
>>           Reporter: dullfire@yahoo.com
>>         Regression: No
>>
>> Created attachment 307241
>>   --> https://bugzilla.kernel.org/attachment.cgi?id=307241&action=edit
>> debug info (some shell commands to check the PCIe devices and drivers)
>>
>> In linux-next (next-20241118), since
>> commit 03cfe0e05650 ("PCI/pwrctl: Ensure that the pwrctl drivers are probed
>> before the PCI client drivers")
>> PCIe drivers no longer bind (at least on the tested SPARCv9 system).
>>
>> It appears a "supplier" devlink is created, however it is are dormant. see
>> attached "bug-info.txt"
> 
> Thanks for the report.  It sounds like you bisected this to
> 03cfe0e05650?  Can you attach a complete dmesg log to the bugzilla?
Yes, a bisect pointed at 03cfe0e05650. After finding that I tried the patch below
to verify, since a trivial revert wasn't possible on next-20241118, and the PCIe
drivers started binding again, and everything seemed functional.

diff --git a/drivers/pci/bus.c b/drivers/pci/bus.c
index b0e3cfdaa276..6d87773784b9 100644
--- a/drivers/pci/bus.c
+++ b/drivers/pci/bus.c
@@ -404,7 +404,7 @@ void pci_bus_add_device(struct pci_dev *dev)
         * PCI client drivers.
         */
        pdev = of_find_device_by_node(dn);
-       if (pdev) {
+       if (pdev && false) {
                if (!device_link_add(&dev->dev, &pdev->dev,
                                     DL_FLAG_AUTOREMOVE_CONSUMER))
                        pci_err(dev, "failed to add device link between %s and %s\n",

Obviously not a fix, but it did help verify the issue.
> 
> This commit is queued for v6.13, and the merge window is now open, so
> if it's a regression, we need to resolve it or drop it ASAP.

Regards,
Jonathan Currier