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clk: qcom: reset: Ensure write completion on reset de/assertion

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Trying to toggle the resets in a rapid fashion can lead to the changes
not actually arriving at the clock controller block when we expect them
to. This was observed at least on SM8250.

Read back the value after regmap_update_bits to ensure write completion.

Fixes: b36ba30c8ac6 ("clk: qcom: Add reset controller support")
Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Link: https://lore.kernel.org/r/20240105-topic-venus_reset-v2-3-c37eba13b5ce@linaro.org
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
This commit is contained in:
Konrad Dybcio 2024-02-06 19:43:36 +01:00 committed by Bjorn Andersson
parent eda40d9c58
commit 2f8cf2c3f3
1 changed files with 6 additions and 1 deletions
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7
drivers/clk/qcom/reset.c
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@ -33,7 +33,12 @@ static int qcom_reset_set_assert(struct reset_controller_dev *rcdev,
map = &rst->reset_map[id]; map = &rst->reset_map[id];
mask = map->bitmask ? map->bitmask : BIT(map->bit); mask = map->bitmask ? map->bitmask : BIT(map->bit);
return regmap_update_bits(rst->regmap, map->reg, mask, assert ? mask : 0); regmap_update_bits(rst->regmap, map->reg, mask, assert ? mask : 0);
/* Read back the register to ensure write completion, ignore the value */
regmap_read(rst->regmap, map->reg, &mask);
return 0;
} }
static int qcom_reset_assert(struct reset_controller_dev *rcdev, unsigned long id) static int qcom_reset_assert(struct reset_controller_dev *rcdev, unsigned long id)