Messages in this thread | | | Date | Tue, 03 Jul 2018 19:40:46 +0530 | From | poza@codeauro ... | Subject | Re: [PATCH V5 3/3] PCI: Mask and unmask hotplug interrupts during reset |
| |
On 2018-07-03 19:29, Lukas Wunner wrote: > On Tue, Jul 03, 2018 at 09:31:24AM -0400, Sinan Kaya wrote: >> Issue is observing hotplug link down event in the middle of AER >> recovery >> as in my previous reply. >> >> If we mask hotplug interrupts before secondary bus reset via my patch, >> then hotplug driver will not observe both link up and link down >> interrupts. >> >> If we don't mask hotplug interrupts, we have a race condition. > > I assume that a bus reset not only causes a link and presence event but > also clears the Presence Detect State bit in the Slot Status register > and the Data Link Layer Link Active bit in the Link Status register > momentarily. > > pciehp may access those two bits concurrently to the AER driver > performing a slot reset. So it may not be sufficient to mask > the interrupt.
Was just wondering that you are protecting Presence Detect State bit with reset_lock, mainly in pciehp_ist but with hotplug interrupt disabled, is there another way that it hotplug code gets activated ?
> > I've posted this patch to address the issue: > https://patchwork.ozlabs.org/patch/930391/ > > Thanks, > > Lukas
| |