From 82e23fa9ae0c0fa7f1766ebf5f5a2c416d5669dd Mon Sep 17 00:00:00 2001 From: Daogao Xu Date: Thu, 28 Feb 2019 15:01:10 +0800 Subject: [PATCH] i2c: add retry-process when slave NACK. [1/1] PD#SWPL-4761 Problem: When slave device is busy processing, it is unable to handle the incoming communication attempts. i2c master have to repeatedly attemp communication until the slave sends an ACK after receiving its slave address. Solution: add retry-process when slave NACK. Verify: mesonaxg_s420_32_release Change-Id: Ieb195176cac4b80e223ea6adb502ffd3bc9ef728 Signed-off-by: Daogao Xu --- drivers/amlogic/i2c/i2c-meson-master.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/drivers/amlogic/i2c/i2c-meson-master.c b/drivers/amlogic/i2c/i2c-meson-master.c index 8bd7d4797ed5..b5280102d344 100644 --- a/drivers/amlogic/i2c/i2c-meson-master.c +++ b/drivers/amlogic/i2c/i2c-meson-master.c @@ -110,6 +110,7 @@ struct meson_i2c { int count; int pos; int error; + int retries; spinlock_t lock; struct completion done; @@ -324,6 +325,8 @@ static void meson_i2c_prepare_xfer(struct meson_i2c *i2c) if (write) meson_i2c_put_data(i2c, i2c->msg->buf + i2c->pos, i2c->count); + + i2c->retries = 0; } static void meson_i2c_stop(struct meson_i2c *i2c) @@ -346,7 +349,6 @@ static irqreturn_t meson_i2c_irq(int irqno, void *dev_id) spin_lock(&i2c->lock); - meson_i2c_reset_tokens(i2c); ctrl = readl(i2c->regs + REG_CTRL); dev_dbg(i2c->dev, "irq: state %d, pos %d, count %d, ctrl %08x\n", @@ -360,12 +362,15 @@ static irqreturn_t meson_i2c_irq(int irqno, void *dev_id) * condition. */ dev_dbg(i2c->dev, "error bit set\n"); - i2c->error = -ENXIO; - i2c->state = STATE_IDLE; - complete(&i2c->done); + if (++i2c->retries >= i2c->adap.retries) { + i2c->error = -ENXIO; + i2c->state = STATE_IDLE; + complete(&i2c->done); + } goto out; } + meson_i2c_reset_tokens(i2c); switch (i2c->state) { case STATE_READ: if (i2c->count > 0) {