Bartlomiej Zolnierkiewicz wrote:
+ if (chip_type == HPT374 && (PCI_FUNC(dev->devfn) & 1)) { + struct pci_dev *dev1 = pci_get_slot(dev->bus, + dev->devfn - 1);
Can be NULL
Not really. This may not be called if it's NULL -- see hpt374_init_setup(). Maybe worth a comment though...
+ unsigned long io_base = pci_resource_start(dev1, 4);
Kaboom
That was a dud bomb. ;-)
What stops a hot unplug of a 374 from causing that to occur. I don't see
Pinned as in pci_get_device()? If so, see setup-ide.c:ide_scan_pcibus(). The IDE core does that for me.
ide_scan_pcibus() is used iff IDE is built-in.
Moreover pci_get_device() holds reference _only_ to the current PCI device (the reference count to @from PCI device is _always_ decremented).
Indeed... doesn't it look like a buglet in the IDE core?
It is OK, when ide_scan_pcibus() is not used
But whan it is used?
probing is done by PCI layer and it keeps the reference to the PCI device in pci_device_probe().
where you have the other pci_dev pinned on a hotplug on a box set to scan the devices in reverse order
Function 1 will always be skipped, regardless of the scan order.
Yes, but init_chipset_hpt366() will still try to access Function 1
No! Re-read the code please: init_chipset_hpt366() won't be called for function 1 if that one is not detected, and only in this case it does function 0 access to read the saved f_CNT value.
Argh, thinko on my side.
Alas, it's your thinko, *again*. ;-)
Unfortunately patch needs fixing anyway since the new comment is incorrect because the reference is kept by hpt366 driver itself - pci_get_slot() in init_setup_hpt374() - not the IDE core...
Actually, init_setup_hpt374() grabs function 1 to register pair of devices (in hopes that the callers have already "pinned" function 0), and init_chipset_hpt366() "pins" function 0 to read the saved f_CNT.
Thanks, Bart
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