On 06/07/2017 02:53 PM, Simon Glass wrote: > Hi Marek, > > On 7 June 2017 at 06:41, Marek Vasut <[email protected]> wrote: >> On 06/07/2017 02:38 PM, Simon Glass wrote: >>> +Tom for comment >>> >>> Hi Marek, >>> >>> On 7 June 2017 at 00:27, Marek Vasut <[email protected]> wrote: >>>> On 06/07/2017 02:16 AM, Simon Glass wrote: >>>>> Hi, >>>>> >>>>> On 6 June 2017 at 17:59, Dr. Philipp Tomsich >>>>> <[email protected]> wrote: >>>>>> Simon, >>>>>> >>>>>>> On 06 Jun 2017, at 23:09, Simon Glass <[email protected]> wrote: >>>>>>> >>>>>>> Hi Philipp, >>>>>>> >>>>>>> On 6 June 2017 at 07:42, Philipp Tomsich >>>>>>> <[email protected]> wrote: >>>>>>>> The regs_otg field in uintptr_t of the platform data structure for >>>>>>>> dwc2-otg has thus far been an unsigned int, but will eventually be >>>>>>>> casted into a void*. >>>>>>>> >>>>>>>> This raises the following error with GCC 6.3 and buildman: >>>>>>>> ../drivers/usb/gadget/dwc2_udc_otg.c: In function 'dwc2_udc_probe': >>>>>>>> ../drivers/usb/gadget/dwc2_udc_otg.c:821:8: warning: cast to pointer >>>>>>>> from integer of different size [-Wint-to-pointer-cast] >>>>>>>> reg = (struct dwc2_usbotg_reg *)pdata->regs_otg; >>>>>>>> ^ >>>>>>>> >>>>>>>> This changes regs_otg to a uintptr_t to ensure that it is large enough >>>>>>>> to hold any valid pointer (and fix the associated warning). >>>>>>>> >>>>>>>> Signed-off-by: Philipp Tomsich <[email protected]> >>>>>>>> >>>>>>>> --- >>>>>>>> >>>>>>>> Changes in v2: >>>>>>>> - (new patch) fix a int-to-pointer cast warning for regs_otg in >>>>>>>> dwc2-otg to fix a buildman failure for u-boot-rockchip/master@2b19b2f >>>>>>>> >>>>>>>> include/usb/dwc2_udc.h | 2 +- >>>>>>>> 1 file changed, 1 insertion(+), 1 deletion(-) >>>>>>>> >>>>>>>> diff --git a/include/usb/dwc2_udc.h b/include/usb/dwc2_udc.h >>>>>>>> index 7324d8a..1a370e0 100644 >>>>>>>> --- a/include/usb/dwc2_udc.h >>>>>>>> +++ b/include/usb/dwc2_udc.h >>>>>>>> @@ -16,7 +16,7 @@ struct dwc2_plat_otg_data { >>>>>>>> int phy_of_node; >>>>>>>> int (*phy_control)(int on); >>>>>>>> unsigned int regs_phy; >>>>>>>> - unsigned int regs_otg; >>>>>>>> + uintptr_t regs_otg; >>>>>>> >>>>>>> Can you use ulong instead? >>>>>> >>>>>> Sure, but can I first ask “why?”. >>>>>> I may reopen an old discussion with this… if so, forgive my ignorance: >>>>>> >>>>>> uintptr_t makes the most sense for this use case in the C99 (or later) >>>>>> type system, >>>>>> as we want this field to hold an integer (i.e. the address from the >>>>>> physical memory >>>>>> map for one of the register blocks) that will be casted into a pointer. >>>>>> The uintptr_t type will always the matching size in any and all >>>>>> programming models; >>>>>> in contrast, ulong would be wrong for LLP64 (and LLP64 probably “doesn’t >>>>>> matter” >>>>>> in the context of U-Boot anyway). >>>>>> >>>>>> What I always found odd, was that uintptr_t is optional according to >>>>>> ISO9899. >>>>>> I would thus not have been surprised if there’s a concern for >>>>>> portability between >>>>>> compilers behind this, but then again … U-Boot makes extensive use of GCC >>>>>> extensions (such as inline assembly). >>>>>> >>>>>> So I am apparently missing something here. >>>>> >>>>> I don't know of any deep reason except that long is defined to be able >>>>> to hold an address, and ulong makes sense since an address is >>>>> generally considered unsigned. >>>>> >>>>> U-Boot by convention uses ulong for addresses. >>>> >>>> I was under the impression that u-boot by convention uses uintptr_t for >>>> addresses. >>>> >>>>> You can see this all >>>>> around the code base so I am really just arguing in favour of >>>>> consistency (and I suppose ulong is easier to type!) >>>> >>>> Then I guess half of the codebase is inconsistent. >>> >>> Actually about 10%: >>> >>> git grep uintptr_t |wc -l >>> 395 >>> git grep ulong |wc -l >>> 4024 >> >> I don't think this is a valid way to count it at all, since uintptr_t is >> only used for casting pointer to number, while ulong is used for >> arbitrary numbers. >> >>> Clearly we use ulong all over the place for addresses - see image.c, >>> most commands, etc. >> >> But none of those use ulong as device address pointers . > > Is there a distinction between a device address pointer and some other > type of address?
ulong is not used only for addresses, which your metric doesn't account for. -- Best regards, Marek Vasut _______________________________________________ U-Boot mailing list [email protected] https://lists.denx.de/listinfo/u-boot
