Re: [PATCH] clk: sunxi-ng: common: Don't call hw_to_ccu_common on hw without common

Frank Oltmanns frank@oltmanns.dev 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@buckeyemail.osu.edu Closes: https://lore.kernel.org/lkml/DM6PR01MB58047C810DDD5D0AE397CADFF7C22@DM6PR01M... Cc: stable@vger.kernel.org Signed-off-by: Frank Oltmanns frank@oltmanns.dev

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Robert, could you please test if this fixes the issue you reported.

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"

This does indeed fix it. 6.9 is still broken, though, but that's probably for other reasons.

Thanks, Frank

[1]: https://lore.kernel.org/lkml/yw1xo78z8ez0.fsf@mansr.com/

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@oltmanns.dev