Re: drivers/clk/clk-divider.c:39:17: sparse: sparse: incorrect type in argument 1 (different base types)

[Stephen Boyd]

Quoting kernel test robot (2020-06-21 02:05:20)
> Hi Stephen,
> 
> First bad commit (maybe != root cause):
> 
> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> head:   64677779e8962c20b580b471790fe42367750599
> commit: bbd7ffdbef6888459f301c5889f3b14ada38b913 clk: Allow the common clk framework to be selectable
> date:   7 weeks ago
> config: alpha-randconfig-s032-20200621 (attached as .config)
> compiler: alpha-linux-gcc (GCC) 9.3.0
> reproduce:
>         # apt-get install sparse
>         # sparse version: v0.6.2-rc2-13-gc59158c8-dirty
>         git checkout bbd7ffdbef6888459f301c5889f3b14ada38b913
>         # save the attached .config to linux build tree
>         make W=1 C=1 ARCH=alpha CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__'
> 
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot <lkp@xxxxxxxxx>
> 
> 
> sparse warnings: (new ones prefixed by >>)
> 
>    drivers/clk/clk-divider.c:31:24: sparse: sparse: cast to restricted __be32
>    drivers/clk/clk-divider.c:31:24: sparse: sparse: cast to restricted __be32
>    drivers/clk/clk-divider.c:31:24: sparse: sparse: cast to restricted __be32
>    drivers/clk/clk-divider.c:31:24: sparse: sparse: cast to restricted __be32
>    drivers/clk/clk-divider.c:31:24: sparse: sparse: cast to restricted __be32
>    drivers/clk/clk-divider.c:31:24: sparse: sparse: cast to restricted __be32
>    drivers/clk/clk-divider.c:31:24: sparse: sparse: cast to restricted __be32
>    drivers/clk/clk-divider.c:31:24: sparse: sparse: cast to restricted __be32
>    drivers/clk/clk-divider.c:31:24: sparse: sparse: cast to restricted __be32
>    drivers/clk/clk-divider.c:31:24: sparse: sparse: cast to restricted __be32
>    drivers/clk/clk-divider.c:31:24: sparse: sparse: cast to restricted __be32
>    drivers/clk/clk-divider.c:31:24: sparse: sparse: cast to restricted __be32
>    drivers/clk/clk-divider.c:31:24: sparse: sparse: cast to restricted __be32
>    drivers/clk/clk-divider.c:31:24: sparse: sparse: cast to restricted __be32
>    drivers/clk/clk-divider.c:31:24: sparse: sparse: cast to restricted __be32
>    drivers/clk/clk-divider.c:31:24: sparse: sparse: cast to restricted __be32
>    drivers/clk/clk-divider.c:31:24: sparse: sparse: cast to restricted __be32
>    drivers/clk/clk-divider.c:31:24: sparse: sparse: cast to restricted __be32
> >> drivers/clk/clk-divider.c:39:17: sparse: sparse: incorrect type in argument 1 (different base types) @@     expected unsigned int [usertype] @@     got restricted __be32 [usertype] @@
> >> drivers/clk/clk-divider.c:39:17: sparse:     expected unsigned int [usertype]
>    drivers/clk/clk-divider.c:39:17: sparse:     got restricted __be32 [usertype]
> 
> vim +39 drivers/clk/clk-divider.c
> 
> 9d9f78ed9af0e4 Mike Turquette 2012-03-15  17  
> 9d9f78ed9af0e4 Mike Turquette 2012-03-15  18  /*
> 9d9f78ed9af0e4 Mike Turquette 2012-03-15  19   * DOC: basic adjustable divider clock that cannot gate
> 9d9f78ed9af0e4 Mike Turquette 2012-03-15  20   *
> 9d9f78ed9af0e4 Mike Turquette 2012-03-15  21   * Traits of this clock:
> 9d9f78ed9af0e4 Mike Turquette 2012-03-15  22   * prepare - clk_prepare only ensures that parents are prepared
> 9d9f78ed9af0e4 Mike Turquette 2012-03-15  23   * enable - clk_enable only ensures that parents are enabled
> 9556f9dad8f576 Brian Norris   2015-04-13  24   * rate - rate is adjustable.  clk->rate = ceiling(parent->rate / divisor)
> 9d9f78ed9af0e4 Mike Turquette 2012-03-15  25   * parent - fixed parent.  No clk_set_parent support
> 9d9f78ed9af0e4 Mike Turquette 2012-03-15  26   */
> 9d9f78ed9af0e4 Mike Turquette 2012-03-15  27  
> 434d69fad63b44 Jonas Gorski   2019-04-18  28  static inline u32 clk_div_readl(struct clk_divider *divider)
> 434d69fad63b44 Jonas Gorski   2019-04-18  29  {
> 434d69fad63b44 Jonas Gorski   2019-04-18  30    if (divider->flags & CLK_DIVIDER_BIG_ENDIAN)
> 434d69fad63b44 Jonas Gorski   2019-04-18 @31            return ioread32be(divider->reg);

Ok. I guess we'll need to force cast the pointer to be __be32 in this
case. Before it wasn't in generic code so the architecture was masking
the issue.