On Wed, 2018-04-11 at 23:39 +0800, Jia-Ju Bai wrote: > de4x5_hw_init() is never called in atomic context. > > de4x5_hw_init() is only called by de4x5_pci_probe(), which is only > set as ".probe" in struct pci_driver. > > Despite never getting called from atomic context, de4x5_hw_init() > calls mdelay() to busily wait. This is not necessary and can be > replaced with usleep_range() to avoid busy waiting. > > This is found by a static analysis tool named DCNS written by myself. > And I also manually check it.
Did you actually test this? The usual reason for wanting m/udelay is that the timing must be exact. The driver is filled with mdelay()s for this reason. The one you've picked on is in the init path so it won't affect the runtime in any way. I also don't think we have the hrtimer machinery for usleep_range() to work properly on parisc, so I don't think the replacement works. James