On Mon, May 03, 2021 at 04:44:24PM +0300, Andy Shevchenko wrote: > On Mon, May 03, 2021 at 03:11:40PM +0200, Frieder Schrempf wrote: > > Hi, > > > > with kernel 5.10.x and 5.12.x I'm getting a null pointer dereference > > exception from the mcp251x driver when I resume from sleep (see trace > > below). > > > > As far as I can tell this was working fine with 5.4. As I currently don't > > have the time to do further debugging/bisecting, for now I want to at least > > report this here. > > > > Maybe there is someone around who could already give a wild guess for what > > might cause this just by looking at the trace/code!? > > Does revert of c7299fea6769 ("spi: Fix spi device unregister flow") help? Other than that, bisecting will take not more than 3-4 iterations only: % git log --oneline v5.4..v5.10.34 -- drivers/net/can/spi/mcp251x.c 3292c4fc9ce2 can: mcp251x: fix support for half duplex SPI host controllers e0e25001d088 can: mcp251x: add support for half duplex controllers 74fa565b63dc can: mcp251x: Use readx_poll_timeout() helper 2d52dabbef60 can: mcp251x: add GPIO support cfc24a0aa7a1 can: mcp251x: sort include files alphabetically df561f6688fe treewide: Use fallthrough pseudo-keyword 8ce8c0abcba3 can: mcp251x: only reset hardware as required 877a902103fd can: mcp251x: add mcp251x_write_2regs() and make use of it 50ec88120ea1 can: mcp251x: get rid of legacy platform data 14684b93019a Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net -- With Best Regards, Andy Shevchenko