Hi Jesse,
Il giorno 14 feb 2021, alle ore 03:58, Jesse T mr.bossman075@gmail.com ha scritto:
This looks good to me, and helps beginners like me. As for the function itself, i have 2 concerns: If it does return a negative value why is it unsigned, if it is in fact signed that a clock above 2.2Ghz is a negative number.
I was worried too at first sight but if you try to check negative numbers you see that -1 is 0xFFFFFFFF so in the worst case you only loose 4095 numbers from the maximum, try to check with hex calculator. And that is the trick.
As for the IS_ERR_VALUE macro there still is a chance that it will error if the clock just so happens to be 2^31 through 2^31 + number of err values.
This is answered from above and IS_ERR_VALUE is a very contracted macro that basically let you to keep value NOT valid if (0 > value > 4095).
Just voicing my concerns i assume as i learn more about uboot, linux,rtos's and different programs there will be minor issues like this.
Sure, no problem :-)
Giulio
On Sat, Feb 13, 2021 at 9:17 PM Giulio Benetti giulio.benetti@benettiengineering.com wrote: Improve clk_get_rate() @return documentation that otherwise is a bit ambiguous. At the moment I expect to return 0 as error since the return type is 'ulong', instead the function really returns negative value in case the corresponding function pointer is null and returns 0 if the clock is invalid.
Signed-off-by: Giulio Benetti giulio.benetti@benettiengineering.com
V1->V2:
- previous comment was wrong, this function returns negative value, so let's improve it's @return documentation as suggested by Simon Glass
include/clk.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/include/clk.h b/include/clk.h index ca6b85fa6f..5a8c7244d0 100644 --- a/include/clk.h +++ b/include/clk.h @@ -344,7 +344,8 @@ int clk_free(struct clk *clk);
- @clk: A clock struct that was previously successfully requested by
clk_request/get_by_*().
- @return clock rate in Hz, or -ve error code.
- @return clock rate in Hz on success, 0 for invalid clock, or -ve error code
*/
for other errors.ulong clk_get_rate(struct clk *clk);
-- 2.25.1