Re: [RFT PATCH] clk: qcom: dispcc-x1e80100: Fix (possibly) dumping regmap

[Daniel J Blueman]

On Tue, 5 May 2026 at 23:29, Krzysztof Kozlowski
<krzysztof.kozlowski@xxxxxxxxxxxxxxxx> wrote:
>
> Reading few registers at the end of the block (e.g. 0x10000, 0x10004)
> might result in synchronous external abort, so limit the regmap to the
> last readable register which allows dumping the regs for debugging.
>
> Reported-by: Daniel J Blueman <daniel@xxxxxxxxx>
> Closes: https://lore.kernel.org/r/CAMVG2su+V5fcZ9LOC0Qm3bpfnhpbmQdJackc7-RvfztDL_dajw@xxxxxxxxxxxxxx/
> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxxxxxxxx>
> ---
>
> Not really tested, just idea based on sm8750 and datasheet/manual.
>
>  drivers/clk/qcom/dispcc-x1e80100.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/clk/qcom/dispcc-x1e80100.c b/drivers/clk/qcom/dispcc-x1e80100.c
> index aa7fd43969f9..575ba90d2070 100644
> --- a/drivers/clk/qcom/dispcc-x1e80100.c
> +++ b/drivers/clk/qcom/dispcc-x1e80100.c
> @@ -1634,7 +1634,7 @@ static const struct regmap_config disp_cc_x1e80100_regmap_config = {
>         .reg_bits = 32,
>         .reg_stride = 4,
>         .val_bits = 32,
> -       .max_register = 0x11008,
> +       .max_register = 0xf004, /* 0x10000, 0x10004 and maybe others are for TZ */
>         .fast_io = true,
>  };

Great work! With this change, no system hangs are observed reading
/sys/kernel/debug/regmap/af00000.clock-controller/registers on my X1
setup. This and the same fix for the other clock controllers are a top
candidate for -stable.

Tested-by: Daniel J Blueman <daniel@xxxxxxxxx>

Thanks,
  Dan

--
Daniel J Blueman