On Mon, Oct 31, 2022 at 09:57:51AM +0800, chenweilong wrote: > On 2022/10/31 6:01, Andy Shevchenko wrote: > > On Sat, Oct 29, 2022 at 07:59:36PM +0800, Weilong Chen wrote: > >> The HiSilicon I2C controller can be used on embedded platform, which > >> boot from devicetree. > > ... > > > >> +#include <linux/acpi.h> > >> +#include <linux/of.h> > > Why? > > > > ... > > > >> +#ifdef CONFIG_ACPI > > Why? > > > > ... > > > >> +#ifdef CONFIG_OF > > Why? > > > > ... > > > >> - .acpi_match_table = hisi_i2c_acpi_ids, > >> + .acpi_match_table = ACPI_PTR(hisi_i2c_acpi_ids), > > Why? > > > > ... > > > >> + .of_match_table = of_match_ptr(hisi_i2c_dts_ids), > > Why of_match_ptr()? > > There's a lot of drivers use of_match_ptr/ACPI_PTR to protect the of_device_id and > have explicit headers file references to linux/acpi.h or linux/of.h, such as > drivers/media/platform/intel/pxa_camera.c, > bluetooth/hci_intel.c, > platform/x86/intel/chtwc_int33fe.c, > platform/x86/intel/pmc/core.c and so on. We have a lot of the legacy or not-up-to-dated to all new kernel APIs code. Does it justify not to use the new approach in the new contribution? ... > The acpi.h and of.h have a nice function or macro definition if CONFIG_OF/ACPI is not satisfy, > for example: > > #define ACPI_PTR(_ptr) (_ptr) vs #define ACPI_PTR(_ptr) (NULL) > > and also a lot of 'static inline' function there. And why do you need it? ... > Seems a good idea to remove all of them, the codes your noted may look a bit > verbose there. But I think it is valuable for a driver and device ,telling > users it support acpi boot or is it just embedded. So, what do we gain here? (Fill the "Advantages of your code" section below) Disadvantages of your code: - ugly ifdeffery which we usually do not appreciate - in some cases it's good to have OF ID table on ACPI platforms (see what PRP0001 trick is) - use old approach for the compiler on how to avoid warnings of the static variables being defined and not used (note, neither ACPI_PTR() nor of_match_ptr() provides a new approach on that, so you have to amend them first) - as a side effect additional headers to be included that are used for 1% or less of their capacity and slow down the compilation -- With Best Regards, Andy Shevchenko
