On 01/12/2022 10:01, Arnd Bergmann wrote: > On Thu, Dec 1, 2022, at 09:06, Greg Kroah-Hartman wrote: >> On Thu, Dec 01, 2022 at 11:13:31AM +0900, Daehwan Jung wrote: >>> This driver works with xhci platform driver. It needs to override >>> functions of xhci_plat_hc_driver. Wakelocks are used for sleep/wakeup >>> scenario of system. >> >> So this means that no other platform xhci driver can be supported in the >> same system at the same time. >> >> Which kind of makes sense as that's not anything a normal system would >> have, BUT it feels very odd. This whole idea of "override the platform >> driver" feels fragile, why not make these just real platform drivers and >> have the xhci platform code be a library that the other ones can use? >> That way you have more control overall, right? > > Agreed, having another layer here (hcd -> xhci -> xhcd_platform -> > xhcd_exynos) would fit perfectly well into how other SoC specific > drivers are abstracted. This could potentially also help reduce > the amount of code duplication between other soc specific variants > (mtk, tegra, mvebu, ...) that are all platform drivers but don't > share code with xhci-plat.c. > > Alternatively, it seems that all of the xhci-exynos support could > just be part of the generic xhci-platform driver: as far as I can > tell, none of the added code is exynos specific at all, instead it > is a generic xhci that is using the wakeup_source framework. There is nothing here Exynos SoC related, it's only for the purpose of using wakelocks. We do not use wakelocks in other drivers, so I wonder what makes this one so special... It does not look like generic approach to the problem (which is BTW not really described in commit). Best regards, Krzysztof
