PCI: Restore assigned resources fully after release

PCI resource fitting code in __assign_resources_sorted() runs in multiple
steps. A resource that was successfully assigned may have to be released
before the next step attempts assignment again. The assign+release cycle is
destructive to a start-aligned struct resource (bridge window or IOV
resource) because the start field is overwritten with the real address when
the resource got assigned.

One symptom:

  pci 0002:00:00.0: bridge window [mem size 0x00100000]: can't assign; bogus alignment

Properly restore the resource after releasing it. The start, end, and flags
fields must be stored into the related struct pci_dev_resource in order to
be able to restore the resource to its original state.

Fixes: 96336ec70264 ("PCI: Perform reset_resource() and build fail list in sync")
Reported-by: Guenter Roeck <linux@roeck-us.net>
Closes: https://lore.kernel.org/r/01eb7d40-f5b5-4ec5-b390-a5c042c30aff@roeck-us.net/
Reported-by: Nicolas Frattaroli <nicolas.frattaroli@collabora.com>
Closes: https://lore.kernel.org/r/3578030.5fSG56mABF@workhorse
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Nicolas Frattaroli <nicolas.frattaroli@collabora.com>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Ondrej Jirman <megi@xff.cz>
Link: https://patch.msgid.link/20250403093137.1481-1-ilpo.jarvinen@linux.intel.com

0 files changed, 0 insertions, 0 deletions