[U-Boot] [PATCH 04/11] net: macb: Fix clk API usage for RISC-V systems

[Simon Glass]

Hi,

On Fri, 18 Jan 2019 at 06:35, Alexander Graf <agraf at suse.de> wrote:
>
>
>
> On 18.01.19 14:28, Anup Patel wrote:
> >
> >
> >> -----Original Message-----
> >> From: Alexander Graf [mailto:agraf at suse.de]
> >> Sent: Friday, January 18, 2019 5:05 PM
> >> To: Anup Patel <Anup.Patel at wdc.com>
> >> Cc: Rick Chen <rick at andestech.com>; Bin Meng <bmeng.cn at gmail.com>;
> >> Joe Hershberger <joe.hershberger at ni.com>; Lukas Auer
> >> <lukas.auer at aisec.fraunhofer.de>; Masahiro Yamada
> >> <yamada.masahiro at socionext.com>; Simon Glass <sjg at chromium.org>;
> >> Palmer Dabbelt <palmer at sifive.com>; Paul Walmsley
> >> <paul.walmsley at sifive.com>; Atish Patra <Atish.Patra at wdc.com>;
> >> Christoph Hellwig <hch at infradead.org>; U-Boot Mailing List <u-
> >> boot at lists.denx.de>
> >> Subject: Re: [PATCH 04/11] net: macb: Fix clk API usage for RISC-V systems
> >>
> >>
> >>
> >>> Am 18.01.2019 um 07:05 schrieb Anup Patel <Anup.Patel at wdc.com>:
> >>>
> >>>
> >>>
> >>>> -----Original Message-----
> >>>> From: Alexander Graf [mailto:agraf at suse.de]
> >>>> Sent: Thursday, January 17, 2019 11:37 PM
> >>>> To: Anup Patel <Anup.Patel at wdc.com>; Rick Chen
> >> <rick at andestech.com>;
> >>>> Bin Meng <bmeng.cn at gmail.com>; Joe Hershberger
> >>>> <joe.hershberger at ni.com>; Lukas Auer
> >>>> <lukas.auer at aisec.fraunhofer.de>; Masahiro Yamada
> >>>> <yamada.masahiro at socionext.com>; Simon Glass <sjg at chromium.org>
> >>>> Cc: Palmer Dabbelt <palmer at sifive.com>; Paul Walmsley
> >>>> <paul.walmsley at sifive.com>; Atish Patra <Atish.Patra at wdc.com>;
> >>>> Christoph Hellwig <hch at infradead.org>; U-Boot Mailing List <u-
> >>>> boot at lists.denx.de>
> >>>> Subject: Re: [PATCH 04/11] net: macb: Fix clk API usage for RISC-V
> >>>> systems
> >>>>
> >>>>> On 01/17/2019 11:38 AM, Anup Patel wrote:
> >>>>> This patch does following fixes in MACB ethernet driver for using it
> >>>>> on RISC-V systems (particularly QEMU sifive_u
> >>>>> machine):
> >>>>> 1. asm/arch/clk.h is not available on RISC-V port so include
> >>>>>    it only for non-RISC-V systems.
> >>>>> 2. Don't fail in macb_enable_clk() if clk_enable() returns
> >>>>>    -ENOSYS because we get -ENOSYS for fixed-rate clocks.
> >>>>>
> >>>>> Signed-off-by: Anup Patel <anup.patel at wdc.com>
> >>>>> Reviewed-by: Bin Meng <bmeng.cn at gmail.com>
> >>>>> ---
> >>>>>  drivers/net/macb.c | 4 +++-
> >>>>>  1 file changed, 3 insertions(+), 1 deletion(-)
> >>>>>
> >>>>> diff --git a/drivers/net/macb.c b/drivers/net/macb.c index
> >>>>> 94c89c762b..9a06b523cc 100644
> >>>>> --- a/drivers/net/macb.c
> >>>>> +++ b/drivers/net/macb.c
> >>>>> @@ -38,7 +38,9 @@
> >>>>>  #include <linux/mii.h>
> >>>>>  #include <asm/io.h>
> >>>>>  #include <asm/dma-mapping.h>
> >>>>> +#ifndef CONFIG_RISCV
> >>>>>  #include <asm/arch/clk.h>
> >>>>> +#endif
> >>>>>  #include <linux/errno.h>
> >>>>>
> >>>>>  #include "macb.h"
> >>>>> @@ -1066,7 +1068,7 @@ static int macb_enable_clk(struct udevice
> >> *dev)
> >>>>>       */
> >>>>>  #ifndef CONFIG_MACB_ZYNQ
> >>>>>      ret = clk_enable(&clk);
> >>>>
> >>>> If clk.h is not available, who exports clk_enable() then; and why is
> >>>> the included needed in the first place?
> >>>
> >>> For some of the ARM boards, clk instances are provided directly by
> >>> arch/arm/mach-xyz sources. For such boards, asm/arch/clk.h is
> >>> required. I think these boards should move to DT based clk drivers.
> >>
> >> Can you at least make this a positive #ifdef then rather than ifndef? We want
> >> to isolate the odd case, not the normal one.
> >>
> >> Maybe you can even find a config option that isolates it further?
> >
> > With the additional check "ret != -ENOSYS", we don't require the #ifndef but
> > someone with Zynq SOC board need to confirm that removing #ifndef won't
> > hurt.
>
> In that case let's CC Michal :).

Yes, although putting an arch-specific #ifdef in a driver is not
correct, so I think the onus would be on Michal to fix that if it were
a problem.

Regards,
Simon