> -----Original Message----- > From: Vitaly Kuznetsov [mailto:vkuznets@xxxxxxxxxx] > Sent: Friday, February 6, 2015 7:04 AM > To: Jake Oshins > Cc: gregkh@xxxxxxxxxxxxxxxxxxx; KY Srinivasan; linux-kernel@xxxxxxxxxxxxxxx; > devel@xxxxxxxxxxxxxxxxxxxxxx; olaf@xxxxxxxxx; apw@xxxxxxxxxxxxx > Subject: Re: [PATCH v2 1/1] drivers:hv:vmbus drivers:hv:vmbus Allow for more > than one MMIO range for children > > Jake Oshins <jakeo@xxxxxxxxxxxxx> writes: > > > This set of changes finds the _CRS object in the ACPI namespace > > that contains memory address space descriptors, intended to convey > > to VMBus which ranges of memory-mapped I/O space are available for > > child devices, and then builds a resource list that contains all > > those ranges. Without this change, only some of the memory-mapped > > I/O space will be available for child devices, and only in some > > virtual BIOS configurations (Generation 2 VMs). > > > > This patch has been updated with feedback from Vitaly Kuznetsov. > > Cleanup is now driven by the acpi remove callback function. > > Sorry for beeing late with this message but I'm seeing issues with this > commit. I added some debug to figure out what's going on and here is > what I see: > > With Gen1 VM we end up doing request_resource for two ranges: > f8000000 - fffbffff > fe0000000 - fffefffff > > request_resource() fails (as we already have PCI device at f8000000 I > suppose?) but we don't check the return value. release_resource on > module unload crashes the kernel: > [ 78.314344] BUG: unable to handle kernel NULL pointer dereference at > 0000000000000030 > [ 78.315021] IP: [<ffffffff8107fac5>] release_resource+0x25/0x90 > [ 78.315021] PGD 78c67067 PUD 78c5a067 PMD 0 > [ 78.315021] Oops: 0000 [#1] SMP DEBUG_PAGEALLOC > [ 78.315021] Modules linked in: hv_vmbus(-) > ... > If I'm not mistaken, before the change we didn't do any > request_resource() for Gen1 VMs at all. > > With Gen2 VM we do request_resource for fe0000000 - fffffffff range > only, that means this commit doesn't change anything. > > Can you please take a look? I'd like to help but I don't completely > understand the essense of the change wrt Gen1 VMs with PCI devices. > I'll take a look immediately. Thanks, Jake _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
