Hi Bryan,
> On 26/04/18 22:21, Marek Vasut wrote:
> > On 04/26/2018 10:47 PM, Bryan O'Donoghue wrote:
> >> Compiling the f_mass_storage driver for an x86 target results in a
> >> compilation error as set_bit and clear_bit are provided by bitops.h
> >>
> >> The local version of set_bit and clear_bit are doing some IP-block
> >> specific bit-twiddling so we don't actually want to accidentally
> >> pick up the bitops.h version of set_bit and clear bit.
> >>
> >> This patch renames to _set_bit() and _clear_bit() respectively to
> >> avoid the namespace collision.
> >>
> >> Signed-off-by: Bryan O'Donoghue <pure.lo...@nexus-software.ie>
> >> Cc: Lukasz Majewski <lu...@denx.de>
> >> Cc: Marek Vasut <ma...@denx.de>
> >> ---
> >> drivers/usb/gadget/f_mass_storage.c | 8 ++++----
> >> 1 file changed, 4 insertions(+), 4 deletions(-)
> >>
> >> diff --git a/drivers/usb/gadget/f_mass_storage.c
> >> b/drivers/usb/gadget/f_mass_storage.c index 1ecb92ac6b..524c43419f
> >> 100644 --- a/drivers/usb/gadget/f_mass_storage.c
> >> +++ b/drivers/usb/gadget/f_mass_storage.c
> >> @@ -283,7 +283,7 @@ static const char fsg_string_interface[] =
> >> "Mass Storage"; struct kref {int x; };
> >> struct completion {int x; };
> >>
> >> -inline void set_bit(int nr, volatile void *addr)
> >> +inline void _set_bit(int nr, volatile void *addr)
> >
> > Do not name functions with _ prefix. Also, I think the suggestion
> > from Lukasz was better.
> >
>
> Funny - I had assumed we were seting the bit like this for a good
> reason but...
>
> This code seems to be something that just crept in along the way
>
> inline void set_bit(int nr, volatile void *addr)
> {
> int mask;
> unsigned int *a = (unsigned int *) addr;
>
> a += nr >> 5;
> mask = 1 << (nr & 0x1f);
> *a |= mask;
> }
>
> but on Linux the upstream driver actually does arch-specific
> set_bit/clear_bit
>
> Looking at it a bit more.. I'm not quite sure how/why we are setting
> the bit like that
>
> git blame drivers/usb/gadget/f_mass_storage.c
>
> b4d36f6809f (Piotr Wilczek 2013-03-05 12:10:16 +0100 286)
> inline void set_bit(int nr, volatile void *addr)
>
> The f_mass_storage.c source file from v2.6.36 Linux kernel.
>
> commit 8876f5e7d3b2a320777dd4f6f5301d474c97a06c
> Author: Michal Nazarewicz <m.nazarew...@samsung.com>
> Date: Mon Jun 21 13:57:09 2010 +0200
>
>
> linux$ git checkout 8876f5e7d3b2a320777dd4f6f5301d474c97a06c --
> drivers/usb/gadget/f_mass_storage.c
>
> Doesn't have a local copy of set_bit/clear_bit at all, which is
> confusing - I guess bitops.h in 2013 didn't have set_bit/clear_bit..
>
> But yeah - I guess we really should be using arch-specific
> get_bit/set_bit after all...+1 > > --- > bod > Best regards, Lukasz Majewski -- DENX Software Engineering GmbH, Managing Director: Wolfgang Denk HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: w...@denx.de
pgpCDZOEPONag.pgp
Description: OpenPGP digital signature
_______________________________________________ U-Boot mailing list U-Boot@lists.denx.de https://lists.denx.de/listinfo/u-boot
