Re: clk: samsung: add infrastructure to register cpu clocks

[Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>]

On Friday, June 26, 2015 01:47:32 PM Dan Carpenter wrote:
> On Fri, Jun 26, 2015 at 12:20:35PM +0200, Bartlomiej Zolnierkiewicz wrote:
> > 
> > Hi,
> > 
> > On Friday, June 26, 2015 07:03:25 PM Krzysztof Kozlowski wrote:
> > > 2015-06-26 18:54 GMT+09:00 Dan Carpenter <dan.carpenter@oracle.com>:
> > > > Hello Thomas Abraham,
> > > >
> > > > The patch ddeac8d968d4: "clk: samsung: add infrastructure to register
> > > > cpu clocks" from Apr 3, 2015, leads to the following static checker
> > > > warning:
> > > >
> > > >         drivers/clk/samsung/clk-cpu.c:164 exynos_cpuclk_pre_rate_change()
> > > >         warn: test_bit() takes a bit number
> > > >
> > > > drivers/clk/samsung/clk-cpu.c
> > > >    158          /*
> > > >    159           * For the selected PLL clock frequency, get the pre-defined divider
> > > >    160           * values. If the clock for sclk_hpm is not sourced from apll, then
> > > >    161           * the values for DIV_COPY and DIV_HPM dividers need not be set.
> > > >    162           */
> > > >    163          div0 = cfg_data->div0;
> > > >    164          if (test_bit(CLK_CPU_HAS_DIV1, &cpuclk->flags)) {
> > > >                              ^^^^^^^^^^^^^^^^
> > > > CLK_CPU_HAS_DIV1 is (1 << 0).  We sometimes used it correctly as a mask
> > > > and sometimes incorrectly (like here) as a bit number.
> > 
> > Fortunately the current value of this flag is "1" so test_bit() still
> > works correctly.  I'll fix it up later anyway.  Thanks for catching it.
> 
> I don't think it works, although I may have misread.  We set BIT(0) in
> exynos4_clk_init() but we test BIT(1) here.

Ah, indeed.  It works because we are always also setting BIT(1) in
exynos4_clk_init().

Best regards,
--
Bartlomiej Zolnierkiewicz
Samsung R&D Institute Poland
Samsung Electronics