Frank Oltmanns <frank@xxxxxxxxxxxx> writes:
> In order to set the rate range of a hw sunxi_ccu_probe calls
> hw_to_ccu_common() assuming all entries in desc->ccu_clks are contained
> in a ccu_common struct. This assumption is incorrect and, in
> consequence, causes invalid pointer de-references.
>
> Remove the faulty call. Instead, add one more loop that iterates over
> the ccu_clks and sets the rate range, if required.
>
> Fixes: b914ec33b391 ("clk: sunxi-ng: common: Support minimum and maximum rate")
> Reported-by: Robert J. Pafford <pafford.9@xxxxxxxxxxxxxxxxxxx>
> Closes: https://lore.kernel.org/lkml/DM6PR01MB58047C810DDD5D0AE397CADFF7C22@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Frank Oltmanns <frank@xxxxxxxxxxxx>
Tested-by: Robert J. Pafford <pafford.9@xxxxxxxxxxxxxxxxxxx>
> ---
> Robert, could you please test if this fixes the issue you reported.
I just applied this patch to my board's kernel, and it fixes the issue.
>
> I'm CC'ing Måns here, because he observed some strange behavior [1] with
> the original patch. Is it possible for you to look into if this patch
> fixes your issue without the need for the following (seemingly
> unrelated) patches:
> cedb7dd193f6 "drm/sun4i: hdmi: Convert encoder to atomic"
> 9ca6bc246035 "drm/sun4i: hdmi: Move mode_set into enable"
> Thanks,
> Frank
>
> [1]: https://lore.kernel.org/lkml/yw1xo78z8ez0.fsf@xxxxxxxxx/
> ---
> drivers/clk/sunxi-ng/ccu_common.c | 18 ++++++++++++------
> 1 file changed, 12 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/clk/sunxi-ng/ccu_common.c b/drivers/clk/sunxi-ng/ccu_common.c
> index ac0091b4ce24..be375ce0149c 100644
> --- a/drivers/clk/sunxi-ng/ccu_common.c
> +++ b/drivers/clk/sunxi-ng/ccu_common.c
> @@ -132,7 +132,6 @@ static int sunxi_ccu_probe(struct sunxi_ccu *ccu, struct device *dev,
>
> for (i = 0; i < desc->hw_clks->num ; i++) {
> struct clk_hw *hw = desc->hw_clks->hws[i];
> - struct ccu_common *common = hw_to_ccu_common(hw);
> const char *name;
>
> if (!hw)
> @@ -147,14 +146,21 @@ static int sunxi_ccu_probe(struct sunxi_ccu *ccu, struct device *dev,
> pr_err("Couldn't register clock %d - %s\n", i, name);
> goto err_clk_unreg;
> }
> + }
> +
> + for (i = 0; i < desc->num_ccu_clks; i++) {
> + struct ccu_common *cclk = desc->ccu_clks[i];
> +
> + if (!cclk)
> + continue;
>
> - if (common->max_rate)
> - clk_hw_set_rate_range(hw, common->min_rate,
> - common->max_rate);
> + if (cclk->max_rate)
> + clk_hw_set_rate_range(&cclk->hw, cclk->min_rate,
> + cclk->max_rate);
> else
> - WARN(common->min_rate,
> + WARN(cclk->min_rate,
> "No max_rate, ignoring min_rate of clock %d - %s\n",
> - i, name);
> + i, clk_hw_get_name(&cclk->hw));
> }
>
> ret = of_clk_add_hw_provider(node, of_clk_hw_onecell_get,
>
> ---
> base-commit: 2607133196c35f31892ee199ce7ffa717bea4ad1
> change-id: 20240622-sunxi-ng_fix_common_probe-5677c3e487fc
>
> Best regards,
> --
>
> Frank Oltmanns <frank@xxxxxxxxxxxx>
>
Thank you,
Robert Pafford <pafford.9@xxxxxxxxxxxxxxxxxxx>
