On Tuesday 07 September 2021 13:22:37 Linus Walleij wrote: > On Wed, Aug 18, 2021 at 1:47 PM Pali Rohár <pali@xxxxxxxxxx> wrote: > > > I do not see any entry in MAINTAINERS file for pci-ftpci100.c driver, so > > I'm not sure to whom should I address this issue... > > It's me. Ok! So could you send update for MAINTAINERS file for this driver? > > During pci-aardvark review, Marc pointed one issue which is currently > > available also in pci-ftpci100.c driver. > > > > When masking or unmasking interrupts there is read-modify-write sequence > > for FARADAY_PCI_CTRL2 register without any locking and is not atomic: > > > > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/pci/controller/pci-ftpci100.c?h=v5.13#n270 > > > > So there is race condition when masking/unmasking more interrupts at the > > same time. > > I thought those operations were called in atomic context. I guess that they cannot be as for performance reasons you could want to mask or unmask more interrupts in parallel on more CPUs. > How did you fix it? Guarding all read-modify-write operations on register by raw spin lock. See: https://lore.kernel.org/linux-pci/20210820155020.3000-1-pali@xxxxxxxxxx/
