On Mon, Mar 22, 2021 at 5:42 PM Rafael J. Wysocki <rafael@xxxxxxxxxx> wrote: > On Mon, Mar 22, 2021 at 4:02 PM Andy Shevchenko > <andy.shevchenko@xxxxxxxxx> wrote: > > On Mon, Mar 22, 2021 at 4:57 PM Rafael J. Wysocki <rafael@xxxxxxxxxx> wrote: > > > On Fri, Mar 19, 2021 at 8:21 PM Andy Shevchenko > > > <andriy.shevchenko@xxxxxxxxxxxxxxx> wrote: > > > > > > > > The decrementation of acpi_device_bus_id->instance_no > > > > in acpi_device_del() is incorrect, because it may cause > > > > a duplicate instance number to be allocated next time > > > > a device with the same acpi_device_bus_id is added. > > > > > > > > Replace above mentioned approach by using IDA framework. > > > > ... > > > > > > + result = ida_simple_get(&acpi_device_bus_id->instance_ida, 0, 255, GFP_KERNEL); > > > > > > This is ida_alloc_range(ida, start, (end) - 1, gfp), so I think it > > > should be 256 above, instead of 255. > > > > Ah, good catch! > > > > > > > While at it, though, there can be more than 256 CPU devices easily on > > > contemporary systems, so I would use a greater number here. Maybe > > > 4096 and define a symbol for it? > > > > I was thinking about it, but there is a problem with the device name, > > since it will break a lot of code, > > What problem is there? If we have only 2 digits, but you are right, we have _at least_ two digits. > > And taking into account that currently we don't change the behaviour > > it is good enough per se as a fix. > > > > That said, we may extend by an additional patch with a logic like this: > > > > res = ida_get(4096) > > if (res < 0) > > return res; > > if (res >= 256) > > use %04x > > else > > use %02x > > > > Would it make sense to you? > > I'm not sure why not to always use %02x ? It doesn't truncate numbers > longer than 2 digits AFAICS. Yeah, should work. Thanks for review, I'll send a new version soon. -- With Best Regards, Andy Shevchenko
