[9810] i2c: exynos5: Binding IRQ for HSI2C latency.

Interrupt and scheduling latency casues the slave timeout failure
during I2C protocol.
This patch binds the I2C IRQ to specified CPUs in order to
reduce these latency

Change-Id: I3fc6459577bac64539d79f5305dd6b3bc3f451fc
Signed-off-by: Kyungwoo Kang <kwoo.kang@samsung.com>

diff --git a/drivers/i2c/busses/i2c-exynos5.c b/drivers/i2c/busses/i2c-exynos5.c
index 8214ea00d9d807d90dbe86f8e549d159f6b2df84..fa1fb664b4ad88f803a70e4a5bcd824654d5a55a 100644 (file)
--- a/drivers/i2c/busses/i2c-exynos5.c
+++ b/drivers/i2c/busses/i2c-exynos5.c
@@ -650,8 +650,11 @@ static int exynos5_i2c_xfer_msg(struct exynos5_i2c *i2c,
        writel(i2c_auto_conf, i2c->regs + HSI2C_AUTO_CONF);
 
        if (operation_mode == HSI2C_INTERRUPT) {
+               unsigned int cpu = raw_smp_processor_id();
                i2c_int_en |= HSI2C_INT_CHK_TRANS_STATE | HSI2C_INT_TRANSFER_DONE;
                writel(i2c_int_en, i2c->regs + HSI2C_INT_ENABLE);
+
+               irq_force_affinity(i2c->irq, cpumask_of(cpu));
                enable_irq(i2c->irq);
        } else {
                writel(HSI2C_INT_TRANSFER_DONE, i2c->regs + HSI2C_INT_ENABLE);