Re: [1/5] clk: divider: read-only divider can propagate rate change

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 01/05/2018 11:09 AM, Jerome Brunet wrote:
When a divider clock has CLK_DIVIDER_READ_ONLY set, it means that the
register shall be left un-touched, but it does not mean the clock
should stop rate propagation if CLK_SET_RATE_PARENT is set

This is properly handled in qcom clk-regmap-divider but it was not in
the generic divider

Fixes: e6d5e7d90be9 ("clk-divider: Fix READ_ONLY when divider > 1")
Signed-off-by: Jerome Brunet <jbrunet@xxxxxxxxxxxx>
---
  drivers/clk/clk-divider.c | 10 ++++++++++
  1 file changed, 10 insertions(+)

diff --git a/drivers/clk/clk-divider.c b/drivers/clk/clk-divider.c
index b49942b9fe50..a851d3e04c7f 100644
--- a/drivers/clk/clk-divider.c
+++ b/drivers/clk/clk-divider.c
@@ -348,6 +348,7 @@ static long clk_divider_round_rate(struct clk_hw *hw, unsigned long rate,
  				unsigned long *prate)
  {
  	struct clk_divider *divider = to_clk_divider(hw);
+	struct clk_hw *hw_parent = clk_hw_get_parent(hw);

Very minor suggestion: This could be moved inside the if block since it is only used there.

  	int bestdiv;
/* if read only, just return current value */
@@ -356,6 +357,15 @@ static long clk_divider_round_rate(struct clk_hw *hw, unsigned long rate,
  		bestdiv &= div_mask(divider->width);
  		bestdiv = _get_div(divider->table, bestdiv, divider->flags,
  			divider->width);
+
+		/* Even a read-only clock can propagate a rate change */
+		if (clk_hw_get_flags(hw) & CLK_SET_RATE_PARENT) {
+			if (!hw_parent)
+				return -EINVAL;
+
+			*prate = clk_hw_round_rate(hw_parent, rate * bestdiv);
+		}
+
  		return DIV_ROUND_UP_ULL((u64)*prate, bestdiv);
  	}

Tested-by: David Lechner <david@xxxxxxxxxxxxxx>
--
To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html



[Index of Archives]     [Linux ARM Kernel]     [Linux ARM]     [Linux Omap]     [Fedora ARM]     [Linux for Sparc]     [IETF Annouce]     [Security]     [Bugtraq]     [Linux MIPS]     [ECOS]     [Asterisk Internet PBX]     [Linux API]

  Powered by Linux