On Wed, Dec 18, 2013 at 03:20:58AM +0000, Rajat Jain wrote: > > > > -----Original Message----- > > From: Bjorn Helgaas [mailto:bhelgaas@xxxxxxxxxx] > > > > [+cc yinghai@xxxxxxxxxx (seems to be Yinghai's preferred email] > > > > On Tue, Dec 17, 2013 at 12:06:05PM -0800, Rajat Jain wrote: > > > We need future link up events for hot-add, thus don't disable the link > > > permanently during device removal. Also, remove the static functions > > > that are now left unused. > > > > The changelog should mention that this reverts part of 2debd9289997 > > ("PCI: > > pciehp: Disable/enable link during slot power off/on"). > > Sure, I'll add that. > > > > > Yinghai, can you tell us whether this is an issue on your systems? > > > > Thanks in advance Yinghai. > > Actually I did not understand the original problem and the solution in the first > place (so I also do not understand how might disabling of presence detect notification > help). If you can give more details on the original problem that shall be great. Here > is what I understood from the commit log: > > The believe the HW looks like this: > > PCIe port <----> Repeater <----> Device. > > An in addition there is the presence detect pin that is connected directly from > The port to the device. Now, when the device is plugged out, the pin indicates > No presence. But are you saying the PCIe link from port to repeater is still up? > > Part of log: > ==================================== > ... > It turns out the root complex is continually trying to train the link to > the repeater because the repeater has not been reset. > > This patch will disable the link at removal time to allow the repeater > to be reset properly. > ... > ==================================== > > 1) I did not understand why would port try to retrain to the link in either cases - > Whether the link to the repeater is up or not? > > 2) When no link is seen, is THAT what causes repeater to go down and hence solve the > Problem? > > 3) I'd expect you'd continuously get "adapter not present" messages if some how > The driver was trying to add the device. But I did not understand where did > "adapter present" messages came from? > > Sorry, but I guess I am totally confused now. I'll probably go to sleep :-) > What, that early ? :-) I think we may have a similar setup on some of our boards. Maybe we can reproduce the situation (after we understand what exactly it is and how to trigger it). Related to this patch set, I learned today that our Space product uses mpt2sas. Just in case we need one for testing reset functionality. Guenter -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
