Re: [RESEND PATCH v2 9/9] ath5k: Constify ioreadX() iomem argument (as in generic implementation)

Krzysztof Kozlowski
2020-02-24T12:47:44Z

On Thu, Feb 20, 2020 at 10:48:33AM +0100, Jiri Slaby wrote:
> On 19. 02. 20, 18:50, Krzysztof Kozlowski wrote:
> > The ioreadX() helpers have inconsistent interface. On some architectures
> > void *__iomem address argument is a pointer to const, on some not.
> >
> > Implementations of ioreadX() do not modify the memory under the address
> > so they can be converted to a "const" version for const-safety and
> > consistency among architectures.
> >
> > Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
> > Acked-by: Kalle Valo <kvalo@codeaurora.org>
> > ---
> > drivers/net/wireless/ath/ath5k/ahb.c | 10 +++++-----
> > 1 file changed, 5 insertions(+), 5 deletions(-)
> >
> > diff --git a/drivers/net/wireless/ath/ath5k/ahb.c b/drivers/net/wireless/ath/ath5k/ahb.c
> > index 2c9cec8b53d9..8bd01df369fb 100644
> > --- a/drivers/net/wireless/ath/ath5k/ahb.c
> > +++ b/drivers/net/wireless/ath/ath5k/ahb.c
> > @@ -138,18 +138,18 @@ static int ath_ahb_probe(struct platform_device *pdev)
> >
> > if (bcfg->devid >= AR5K_SREV_AR2315_R6) {
> > /* Enable WMAC AHB arbitration */
> > - reg = ioread32((void __iomem *) AR5K_AR2315_AHB_ARB_CTL);
> > + reg = ioread32((const void __iomem *) AR5K_AR2315_AHB_ARB_CTL);
>
> While I understand why the parameter of ioread32 should be const, I
> don't see a reason for these casts on the users' side. What does it
> bring except longer code to read?

Because the argument is an int:

drivers/net/wireless/ath/ath5k/ahb.c: In function ‘ath_ahb_probe’:
drivers/net/wireless/ath/ath5k/ahb.c:141:18: warning: passing argument 1 of ‘ioread32’ makes pointer from integer without a cast [-Wint-conversion]
reg = ioread32(AR5K_AR2315_AHB_ARB_CTL);

Best regards,
Krzysztof