Messages in this thread | | | From | Laurent Pinchart <> | Subject | Re: [PATCH] clk: shmobile: div6: Avoid division by zero in .round_rate() | Date | Thu, 05 Feb 2015 19:19:14 +0200 |
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Hi Sergei,
On Thursday 05 February 2015 01:14:46 Sergei Shtylyov wrote: > On 02/05/2015 01:04 AM, Sergei Shtylyov wrote: > >>>>> Anyone may call clk_round_rate() with a zero rate value, so we have to > >>>>> protect against that. > >>>>> > >>>>> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> > >>>> > >>>> Acked-by: Wolfram Sang <wsa+renesas@sang-engineering.com> > >>>> > >>>> I agree that this should not be fixed in the core because the fixup is > >>>> really driver dependant. > >>>> > >>> Dunno, zero frequency seems generally insane to me. > >> > >> It is useful to find the lowest frequency a clock can support. Basically > >> it is a search for the floor frequency. > >> > > Why not just use 1? Or are you assuming that some hardware could actually > > support 0 Hz? > > Replying to myself: yes, this has happened to me, when I forgot to override > the EXTAL frequency in the board .dts file (default was 0).
So it was a good thing that the driver crashed, it let you find a bug ;-)
Jokes aside, a zero frequency is the usual way to find the lowest frequency, but I agree that there aren't many integers between 0 and 1. Mike, do you have an opinion ?
-- Regards,
Laurent Pinchart
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