This is a note to let you know that I've just added the patch titled
pinctrl: qcom: lpass-lpi: fix concurrent register updates
to the 6.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
pinctrl-qcom-lpass-lpi-fix-concurrent-register-updat.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 56c073d6670278d3fe9cd941dfce6507d5ba1f8b
Author: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx>
Date: Fri Oct 13 16:57:05 2023 +0200
pinctrl: qcom: lpass-lpi: fix concurrent register updates
[ Upstream commit c8befdc411e5fd1bf95a13e8744c8ca79b412bee ]
The Qualcomm LPASS LPI pin controller driver uses one lock for guarding
Read-Modify-Write code for slew rate registers. However the pin
configuration and muxing registers have exactly the same RMW code but
are not protected.
Pin controller framework does not provide locking here, thus it is
possible to trigger simultaneous change of pin configuration registers
resulting in non-atomic changes.
Protect from concurrent access by re-using the same lock used to cover
the slew rate register. Using the same lock instead of adding second
one will make more sense, once we add support for newer Qualcomm SoC,
where slew rate is configured in the same register as pin
configuration/muxing.
Fixes: 6e261d1090d6 ("pinctrl: qcom: Add sm8250 lpass lpi pinctrl driver")
Cc: stable@xxxxxxxxxxxxxxx
Reviewed-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20231013145705.219954-1-krzysztof.kozlowski@xxxxxxxxxx
Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/pinctrl/qcom/pinctrl-lpass-lpi.c b/drivers/pinctrl/qcom/pinctrl-lpass-lpi.c
index a55998ae29fa4..bfcc5c45b8fa5 100644
--- a/drivers/pinctrl/qcom/pinctrl-lpass-lpi.c
+++ b/drivers/pinctrl/qcom/pinctrl-lpass-lpi.c
@@ -24,7 +24,8 @@ struct lpi_pinctrl {
char __iomem *tlmm_base;
char __iomem *slew_base;
struct clk_bulk_data clks[MAX_LPI_NUM_CLKS];
- struct mutex slew_access_lock;
+ /* Protects from concurrent register updates */
+ struct mutex lock;
const struct lpi_pinctrl_variant_data *data;
};
@@ -94,9 +95,11 @@ static int lpi_gpio_set_mux(struct pinctrl_dev *pctldev, unsigned int function,
if (WARN_ON(i == g->nfuncs))
return -EINVAL;
+ mutex_lock(&pctrl->lock);
val = lpi_gpio_read(pctrl, pin, LPI_GPIO_CFG_REG);
u32p_replace_bits(&val, i, LPI_GPIO_FUNCTION_MASK);
lpi_gpio_write(pctrl, pin, LPI_GPIO_CFG_REG, val);
+ mutex_unlock(&pctrl->lock);
return 0;
}
@@ -202,14 +205,14 @@ static int lpi_config_set(struct pinctrl_dev *pctldev, unsigned int group,
if (slew_offset == LPI_NO_SLEW)
break;
- mutex_lock(&pctrl->slew_access_lock);
+ mutex_lock(&pctrl->lock);
sval = ioread32(pctrl->slew_base + LPI_SLEW_RATE_CTL_REG);
sval &= ~(LPI_SLEW_RATE_MASK << slew_offset);
sval |= arg << slew_offset;
iowrite32(sval, pctrl->slew_base + LPI_SLEW_RATE_CTL_REG);
- mutex_unlock(&pctrl->slew_access_lock);
+ mutex_unlock(&pctrl->lock);
break;
default:
return -EINVAL;
@@ -225,6 +228,7 @@ static int lpi_config_set(struct pinctrl_dev *pctldev, unsigned int group,
lpi_gpio_write(pctrl, group, LPI_GPIO_VALUE_REG, val);
}
+ mutex_lock(&pctrl->lock);
val = lpi_gpio_read(pctrl, group, LPI_GPIO_CFG_REG);
u32p_replace_bits(&val, pullup, LPI_GPIO_PULL_MASK);
@@ -233,6 +237,7 @@ static int lpi_config_set(struct pinctrl_dev *pctldev, unsigned int group,
u32p_replace_bits(&val, output_enabled, LPI_GPIO_OE_MASK);
lpi_gpio_write(pctrl, group, LPI_GPIO_CFG_REG, val);
+ mutex_unlock(&pctrl->lock);
return 0;
}
@@ -432,7 +437,7 @@ int lpi_pinctrl_probe(struct platform_device *pdev)
pctrl->chip.of_gpio_n_cells = 2;
pctrl->chip.can_sleep = false;
- mutex_init(&pctrl->slew_access_lock);
+ mutex_init(&pctrl->lock);
pctrl->ctrl = devm_pinctrl_register(dev, &pctrl->desc, pctrl);
if (IS_ERR(pctrl->ctrl)) {
@@ -454,7 +459,7 @@ int lpi_pinctrl_probe(struct platform_device *pdev)
return 0;
err_pinctrl:
- mutex_destroy(&pctrl->slew_access_lock);
+ mutex_destroy(&pctrl->lock);
clk_bulk_disable_unprepare(MAX_LPI_NUM_CLKS, pctrl->clks);
return ret;
@@ -466,7 +471,7 @@ int lpi_pinctrl_remove(struct platform_device *pdev)
struct lpi_pinctrl *pctrl = platform_get_drvdata(pdev);
int i;
- mutex_destroy(&pctrl->slew_access_lock);
+ mutex_destroy(&pctrl->lock);
clk_bulk_disable_unprepare(MAX_LPI_NUM_CLKS, pctrl->clks);
for (i = 0; i < pctrl->data->npins; i++)
