On Wed, Jan 13, 2021 at 11:48 PM Andy Shevchenko <andy.shevche...@gmail.com> wrote: > > > > On Monday, December 21, 2020, Jisheng Zhang <jisheng.zh...@synaptics.com> > wrote: >> >> On Thu, 17 Dec 2020 19:16:58 -0800 Saravana Kannan wrote: >> >> >> > >> > >> > As discussed in LPC 2020, cyclic dependencies in firmware that couldn't >> > be broken using logic was one of the last remaining reasons >> > fw_devlink=on couldn't be set by default. >> > >> > This series changes fw_devlink so that when a cyclic dependency is found >> > in firmware, the links between those devices fallback to permissive mode >> > behavior. This way, the rest of the system still benefits from >> > fw_devlink, but the ambiguous cases fallback to permissive mode. >> > >> > Setting fw_devlink=on by default brings a bunch of benefits (currently, >> > only for systems with device tree firmware): >> > * Significantly cuts down deferred probes. >> > * Device probe is effectively attempted in graph order. >> > * Makes it much easier to load drivers as modules without having to >> > worry about functional dependencies between modules (depmod is still >> > needed for symbol dependencies). >> > >> > Greg/Rafael, >> > >> > Can we get this pulled into 5.11-rc1 or -rc2 soon please? I expect to >> > see some issues due to device drivers that aren't following best >> > practices (they don't expose the device to driver core). Want to >> > identify those early on and try to have them fixed before 5.11 release. >> > See [1] for an example of such a case. >> > >> > If we do end up have to revert anything, it'll just be Patch 5/5 (a one >> > liner). >> > >> > Marc, >> > >> > You had hit issues with fw_devlink=on before on some of your systems. >> > Want to give this a shot? >> > >> > Jisheng, >> > >> > Want to fix up one of those gpio drivers you were having problems with? >> > >> >> Hi Saravana, >> >> I didn't send fix for the gpio-dwapb.c in last development window, so can >> send patch once 5.11-rc1 is released. > > > If you are going to do anything with that GPIO driver, it should be removal > of compatible strings from the device child nodes. The driver IIRC never used > them anyhow anyway.
We already discussed this in a different thread. Just deleting DT is not okay. That breaks a new kernel + old DT combo. Upgrading the kernel shouldn't break a board. -Saravana
