irqchip/stm32: Don't set rising configuration registers at init

The rising configuration status register (rtsr) is not banked.
As it is shared with the co-processor, it should not be written at probe
time, else the co-processor configuration will be lost.

Fixes: f9fc1745 ("irqchip/stm32: Add host and driver data structures")
Signed-off-by: Fabien Dessenne <fabien.dessenne@st.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

drivers/irqchip/irq-stm32-exti.c

@@ -716,7 +716,6 @@ stm32_exti_chip_data *stm32_exti_chip_init(struct stm32_exti_host_data *h_data,
 	const struct stm32_exti_bank *stm32_bank;
 	struct stm32_exti_chip_data *chip_data;
 	void __iomem *base = h_data->base;
-	u32 irqs_mask;
 
 	stm32_bank = h_data->drv_data->exti_banks[bank_idx];
 	chip_data = &h_data->chips_data[bank_idx];
@@ -725,10 +724,6 @@ stm32_exti_chip_data *stm32_exti_chip_init(struct stm32_exti_host_data *h_data,
 
 	raw_spin_lock_init(&chip_data->rlock);
 
-	/* Determine number of irqs supported */
-	writel_relaxed(~0UL, base + stm32_bank->rtsr_ofst);
-	irqs_mask = readl_relaxed(base + stm32_bank->rtsr_ofst);
-
 	/*
 	 * This IP has no reset, so after hot reboot we should
 	 * clear registers to avoid residue