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drivers: mcp23xxx: fix deadlock in interrupt callbacks

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Interrupt callbacks may want to configure GPIO pins on the port expander,
e.g. to change the polarity of a level interrupt. This would cause a
deadlock because the callback handler would still be holding the lock.

Signed-off-by: Armin Brauns <armin.brauns@embedded-solutions.at>
This commit is contained in:
Armin Brauns 2023-06-23 08:10:46 +00:00 • committed by Chris Friedt
commit c094bd688a
1 changed files with 7 additions and 4 deletions
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11
drivers/gpio/gpio_mcp23xxx.c
View file

@ -408,7 +408,7 @@ static void mcp23xxx_work_handler(struct k_work *work)
ret = read_port_regs(dev, REG_INTF, &intf);
if (ret != 0) {
LOG_ERR("Failed to read INTF");
goto done;
goto fail;
}
if (!intf) {
@ -416,7 +416,7 @@ static void mcp23xxx_work_handler(struct k_work *work)
* handler had a chance to run
*/
LOG_ERR("Spurious interrupt");
goto done;
goto fail;
}
uint16_t intcap;
@ -425,7 +425,7 @@ static void mcp23xxx_work_handler(struct k_work *work)
ret = read_port_regs(dev, REG_INTCAP, &intcap);
if (ret != 0) {
LOG_ERR("Failed to read INTCAP");
goto done;
goto fail;
}
/* mcp23xxx does not support single-edge interrupts in hardware, filter them out manually */
@ -434,8 +434,11 @@ static void mcp23xxx_work_handler(struct k_work *work)
intf &= level_ints | (intcap & drv_data->rising_edge_ints) |
(~intcap & drv_data->falling_edge_ints);
k_sem_give(&drv_data->lock);
gpio_fire_callbacks(&drv_data->callbacks, dev, intf);
done:
return;
fail:
k_sem_give(&drv_data->lock);
}