> Subject: Re: [PATCH 1/2] clk: imx93: Drop macro IMX93_CLK_END
>
> On 25/06/2024 12:43, Pengfei Li wrote:
> > On Tue, Jun 25, 2024 at 09:44:42AM +0200, Krzysztof Kozlowski
> wrote:
> >> On 25/06/2024 19:51, Pengfei Li wrote:
> >>> IMX93_CLK_END was previously defined in imx93-clock.h to
> indicate
> >>> the number of clocks, but it is not part of the ABI, so it should be
> >>> dropped.
> >>>
> >>> Now, the driver gets the number of clks by querying the maximum
> >>> index in the clk array. Due to the discontinuity in the definition
> >>> of clk index, with some gaps present, the total count cannot be
> >>> obtained by summing the array size.
> >>>
> >>> Signed-off-by: Pengfei Li <pengfei.li_1@xxxxxxx>
> >>> ---
> >>> drivers/clk/imx/clk-imx93.c | 25 +++++++++++++++++++++----
> >>> 1 file changed, 21 insertions(+), 4 deletions(-)
> >>>
> >>> diff --git a/drivers/clk/imx/clk-imx93.c
> >>> b/drivers/clk/imx/clk-imx93.c index c6a9bc8ecc1f..68c929512e16
> >>> 100644
> >>> --- a/drivers/clk/imx/clk-imx93.c
> >>> +++ b/drivers/clk/imx/clk-imx93.c
> >>> @@ -257,6 +257,20 @@ static const struct imx93_clk_ccgr
> { static
> >>> struct clk_hw_onecell_data *clk_hw_data; static struct clk_hw
> >>> **clks;
> >>>
> >>> +static int imx_clks_get_num(void)
> >>> +{
> >>> + u32 val = 0;
> >>> + int i;
> >>> +
> >>> + for (i = 0; i < ARRAY_SIZE(root_array); i++)
> >>> + val = max_t(u32, val, root_array[i].clk);
> >>> +
> >>> + for (i = 0; i < ARRAY_SIZE(ccgr_array); i++)
> >>> + val = max_t(u32, val, ccgr_array[i].clk);
> >>> +
> >>> + return val + 1;
> >>> +}
> >>> +
> >>> static int imx93_clocks_probe(struct platform_device *pdev) {
> >>> struct device *dev = &pdev->dev;
> >>> @@ -264,14 +278,17 @@ static int imx93_clocks_probe(struct
> platform_device *pdev)
> >>> const struct imx93_clk_root *root;
> >>> const struct imx93_clk_ccgr *ccgr;
> >>> void __iomem *base, *anatop_base;
> >>> + int clks_num;
> >>> int i, ret;
> >>>
> >>> + clks_num = imx_clks_get_num();
> >>> +
> >>> clk_hw_data = devm_kzalloc(dev, struct_size(clk_hw_data,
> hws,
> >>> - IMX93_CLK_END),
> GFP_KERNEL);
> >>> + clks_num), GFP_KERNEL);
> >>> if (!clk_hw_data)
> >>> return -ENOMEM;
> >>>
> >>> - clk_hw_data->num = IMX93_CLK_END;
> >>> + clk_hw_data->num = clks_num;
> >>
> >> Why so complicated code instead of pre-processor define or array
> size?
> >>
> >> Best regards,
> >> Krzysztof
> >>
> >>
> >
> > Hi Krzysztof,
> >
> > Thanks for the comment, here are some of our thoughts.
> >
> > Regarding the predefined method, it's easy to forget to update the
> > macro definition when adding some new clocks to imx93-clock.h in
> the future.
>
> Somehow most developers in most platforms can do it... Anyway, that
> would be build time detectable so no problem at all.
>
> >
> > Also, we cannot use the array size method in this scenario, as some
> > unnecessary clocks have been removed in the past, resulting in
> > discontinuous definitions of clock indexes. This means that the
> > maximum clock index can be larger than the allocated clk_hw array
> size. At this point, using the maximum index to access the clk_hw array
> will result in an out of bounds error.
>
> You mix bindings with array entries. That's independent or just clock
> drivers are broken.
But there is issue that binding update and clock driver are normally in
two patches. So if just use the IMX93_CLK_END in this file,
it will be easy to break `git bisect`.
Regards,
Peng.
>
> Best regards,
> Krzysztof
>
