On Tue, Jan 28, 2014 at 05:32:58PM -0500, Joe Lawrence wrote:
> On Tue, 28 Jan 2014 03:32:47 +0300
> Dan Carpenter <dan.carpenter@xxxxxxxxxx> wrote:
>
> > The infinite loop check seems to work pretty well.
>
> This is pretty neat. A question about the warnings out of the ixgb
> driver. For example:
>
> drivers/net/ethernet/intel/ixgb/ixgb_hw.c:777 ixgb_read_phy_reg() warn: this loop depends on readl() succeeding
>
> 767 for (i = 0; i < 10; i++)
> 768 {
> 769 udelay(10);
> 770
> 771 command = IXGB_READ_REG(hw, MSCA);
> 772
> 773 if ((command & IXGB_MSCA_MDI_COMMAND) == 0)
> 774 break;
> 775 }
> 776
> 777 ASSERT((command & IXGB_MSCA_MDI_COMMAND) == 0);
>
> is smatch warning about the for loops or the ASSERT macro?
>
> These particular for(0..9) loops can't loop infinitely. Maybe the
> ASSERT is implemented as a "do {} while(0)" that is triggering the
> warning?
Yes. It's warning about the ASSERT. It's implemented like this:
#define ASSERT(x) BUG_ON(!(x))
#define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while (0)
We never exit the do {} while (0) loop because we hit BUG().
regards,
dan carpenter
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