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Late pin control fixes for the v6.6 kernel cycle:

Browse Source 
- Concurrent register updates in the Qualcomm LPASS pin
   controller gets a proper lock.
 
 - We revert a mutex fix that was causing problems: contention
   on the mutex or something of the sort lead to probe
   reordering and MMC block devices start to register in
   a different order, which unsuspecting userspace is not
   ready to handle.
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Merge tag 'pinctrl-v6.6-3' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl

Pull pin control fixes from Linus Walleij:

 - Concurrent register updates in the Qualcomm LPASS pin controller gets
   a proper lock.

 - revert a mutex fix that was causing problems: contention on the mutex
   or something of the sort lead to probe reordering and MMC block
   devices start to register in a different order, which unsuspecting
   userspace is not ready to handle

* tag 'pinctrl-v6.6-3' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl:
  Revert "pinctrl: avoid unsafe code pattern in find_pinctrl()"
  pinctrl: qcom: lpass-lpi: fix concurrent register updates
This commit is contained in:
Linus Torvalds 2023-10-20 13:21:46 -07:00
commit 659eaa0015
2 changed files with 18 additions and 15 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

16
drivers/pinctrl/core.c
View File

@ -1022,20 +1022,17 @@ static int add_setting(struct pinctrl *p, struct pinctrl_dev *pctldev,
static struct pinctrl *find_pinctrl(struct device *dev)
{
struct pinctrl *entry, *p = NULL;
struct pinctrl *p;
mutex_lock(&pinctrl_list_mutex);
list_for_each_entry(entry, &pinctrl_list, node) {
if (entry->dev == dev) {
p = entry;
kref_get(&p->users);
break;
list_for_each_entry(p, &pinctrl_list, node)
if (p->dev == dev) {
mutex_unlock(&pinctrl_list_mutex);
return p;
}
}
mutex_unlock(&pinctrl_list_mutex);
return p;
return NULL;
}
static void pinctrl_free(struct pinctrl *p, bool inlist);
@ -1143,6 +1140,7 @@ struct pinctrl *pinctrl_get(struct device *dev)
p = find_pinctrl(dev);
if (p) {
dev_dbg(dev, "obtain a copy of previously claimed pinctrl\n");
kref_get(&p->users);
return p;
}

17
drivers/pinctrl/qcom/pinctrl-lpass-lpi.c
View File

@ -32,7 +32,8 @@ 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;
DECLARE_BITMAP(ever_gpio, MAX_NR_GPIO);
const struct lpi_pinctrl_variant_data *data;
};
@ -103,6 +104,7 @@ 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);
/*
@ -128,6 +130,7 @@ static int lpi_gpio_set_mux(struct pinctrl_dev *pctldev, unsigned int function,
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;
}
@ -233,14 +236,14 @@ 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;
@ -256,6 +259,7 @@ 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);
@ -264,6 +268,7 @@ 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;
}
@ -461,7 +466,7 @@ int lpi_pinctrl_probe(struct platform_device *pdev)
pctrl->chip.label = dev_name(dev);
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)) {
@ -483,7 +488,7 @@ 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;
@ -495,7 +500,7 @@ 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++)