Messages in this thread | | | Date | Mon, 5 Sep 2022 08:49:58 -0700 | From | Guenter Roeck <> | Subject | Re: [PATCH v1 10/11] watchdog: bd9576_wdt: switch to using devm_fwnode_gpiod_get() |
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On 9/5/22 08:21, Andy Shevchenko wrote: > On Mon, Sep 5, 2022 at 6:13 PM Guenter Roeck <linux@roeck-us.net> wrote: >> On 9/5/22 04:09, Andy Shevchenko wrote: >>> On Mon, Sep 5, 2022 at 9:33 AM Dmitry Torokhov >>> <dmitry.torokhov@gmail.com> wrote: > > ... > >>>> + count = device_property_count_u32(dev->parent, "rohm,hw-timeout-ms"); >>>> + if (count < 0 && count != -EINVAL) >>>> + return count; >>>> + >>>> + if (count > 0) { >>> >>>> + if (count > ARRAY_SIZE(hw_margin)) >>>> + return -EINVAL; >>> >>> Why double check? You may move it out of the (count > 0). >> >> Two checks will always be needed, so I don't entirely see >> how that would be better. > > But not nested. That's my point: > > if (count > ARRAY_SIZE()) > return ... > if (count > 0) > ... >
The old code has either 1 or two checks if there is no error. Your suggested code has always two checks. I don't see how that is an improvement.
>>>> - if (ret == 1) >>>> - hw_margin_max = hw_margin[0]; >>> >>>> + ret = device_property_read_u32_array(dev->parent, >>>> + "rohm,hw-timeout-ms", >>>> + hw_margin, count); >>>> + if (ret < 0) >>>> + return ret; >>> >>> So, only this needs the count > 0 check since below already has it implicitly. >>> >> Sorry, I don't understand this comment. > > if (count > 0) { > ret = device_property_read_u32_array(...); > ... > } > if (count == 1) > ... > if (count == 2) > ... > > But here it might be better to have the nested conditionals. >
We know that count is either 1 or 2 here, so strictly speaking if (count == 1) { } else { } would be sufficient. On the other side, that depends on ARRAY_SIZE() being exactly 2, so if (count == 1) { } else if (count == 2) { } would also make sense. Either way is fine with me. I'll leave it up to Dmitry to decide what he wants to do.
Thanks, Guenter
>>>> - if (ret == 2) { >>>> - hw_margin_max = hw_margin[1]; >>>> - hw_margin_min = hw_margin[0]; >>>> + if (count == 1) >>>> + hw_margin_max = hw_margin[0]; >>>> + >>>> + if (count == 2) { >>>> + hw_margin_max = hw_margin[1]; >>>> + hw_margin_min = hw_margin[0]; >>>> + } >>>> } >
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