On Tue, Feb 22, 2022 at 10:14:16AM +0100, Jiri Slaby wrote: > On 16. 02. 22, 9:53, Christoph Hellwig wrote: > > On Tue, Feb 15, 2022 at 03:43:59PM +0200, Andy Shevchenko wrote: > > > The pci_iounmap() doesn't cover all the cases where resource should > > > be unmapped. Instead of spreading it more, replace the pci_ioremap_bar() > > > with pcim_iomap() which uses managed resource approach. > > > > pcim_iomap requires the use of ioreadX/iowriteX and thus runtime > > overhead. So in doubt please add a pcim_ioremap_bar instead of forcing > > the legacy iomap/ioread/iowrite API onto modern drivers tht can't > > support legacy port I/O. > > Hmm, the driver combines pci_ioremap_bar with pci_iounmap. pci_iounmap does > the right thing after all, but is that correct? And this driver is not > alone, this shows more: > git grep -E 'pci_iounmap|pci_ioremap_bar' `git grep -l pci_iounmap \`git > grep -l pci_ioremap_bar\`` I think it is wrong. It is not actively harmful unlike the the combination of pci_iomap and then later use of accessors from the ioremap family, but still not exactly a good idea. In a perfect world we'd have some different annotation from __iomem for the whole iomap family of functions.
