On Fri, 24 May 2019 06:48:47 PDT (-0700), andrew@xxxxxxx wrote:
On Fri, May 24, 2019 at 10:22:06AM +0530, Yash Shah wrote:On Thu, May 23, 2019 at 8:24 PM Andrew Lunn <andrew@xxxxxxx> wrote: > > > +static int fu540_macb_tx_set_rate(struct clk_hw *hw, unsigned long rate, > > + unsigned long parent_rate) > > +{ > > + rate = fu540_macb_tx_round_rate(hw, rate, &parent_rate); > > + iowrite32(rate != 125000000, mgmt->reg); > > That looks odd. Writing the result of a comparison to a register? The idea was to write "1" to the register if the value of rate is anything else than 125000000.I'm not a language lawyer. Is it guaranteed that an expression like this returns 1? Any value !0 is true, so maybe it actually returns 42?
From Stack Overflow: https://stackoverflow.com/questions/18097922/return-value-of-operator-in-c
"C11(ISO/IEC 9899:201x) §6.5.8 Relational operators Each of the operators < (less than), > (greater than), <= (less than or equal to), and >= (greater than or equal to) shall yield 1 if the specified relation is true and 0 if it is false. The result has type int."
To make it easier to read, I will change this to below: - iowrite32(rate != 125000000, mgmt->reg); + if (rate != 125000000) + iowrite32(1, mgmt->reg); + else + iowrite32(0, mgmt->reg); Hope that's fine. Thanks for your commentYes, that is good. Andrew
