Re: [PATCH] i2c: aspeed: Adjust spinlock scope in the irq handler

[Jae Hyun Yoo]

On 7/12/2018 1:41 AM, Brendan Higgins wrote:

On Mon, Jul 2, 2018 at 2:40 PM Jae Hyun Yoo
<jae.hyun....@linux.intel.com> wrote:

This patch adjusts spinlock scope to make it wrap the whole irq
handler using a single lock/unlock which covers both master and
slave handlers.

Signed-off-by: Jae Hyun Yoo <jae.hyun....@linux.intel.com>
---
  drivers/i2c/busses/i2c-aspeed.c | 16 ++++++++++------
  1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/drivers/i2c/busses/i2c-aspeed.c b/drivers/i2c/busses/i2c-aspeed.c
index 60e4d0e939a3..9f02aa959a3e 100644
--- a/drivers/i2c/busses/i2c-aspeed.c
+++ b/drivers/i2c/busses/i2c-aspeed.c
@@ -234,7 +234,6 @@ static bool aspeed_i2c_slave_irq(struct aspeed_i2c_bus *bus)
         bool irq_handled = true;
         u8 value;

-       spin_lock(&bus->lock);
         if (!slave) {
                 irq_handled = false;
                 goto out;
@@ -325,7 +324,6 @@ static bool aspeed_i2c_slave_irq(struct aspeed_i2c_bus *bus)
         writel(status_ack, bus->base + ASPEED_I2C_INTR_STS_REG);

  out:
-       spin_unlock(&bus->lock);
         return irq_handled;
  }
  #endif /* CONFIG_I2C_SLAVE */
@@ -389,7 +387,6 @@ static bool aspeed_i2c_master_irq(struct aspeed_i2c_bus 
*bus)
         u8 recv_byte;
         int ret;

-       spin_lock(&bus->lock);
         irq_status = readl(bus->base + ASPEED_I2C_INTR_STS_REG);
         /* Ack all interrupt bits. */
         writel(irq_status, bus->base + ASPEED_I2C_INTR_STS_REG);
@@ -547,22 +544,29 @@ static bool aspeed_i2c_master_irq(struct aspeed_i2c_bus 
*bus)
                 dev_err(bus->dev,
                         "irq handled != irq. expected 0x%08x, but was 
0x%08x\n",
                         irq_status, status_ack);
-       spin_unlock(&bus->lock);
         return !!irq_status;
  }

  static irqreturn_t aspeed_i2c_bus_irq(int irq, void *dev_id)
  {
         struct aspeed_i2c_bus *bus = dev_id;
+       bool ret;
+
+       spin_lock(&bus->lock);

  #if IS_ENABLED(CONFIG_I2C_SLAVE)
         if (aspeed_i2c_slave_irq(bus)) {
                 dev_dbg(bus->dev, "irq handled by slave.\n");
-               return IRQ_HANDLED;
+               ret = true;
+               goto out;
         }
  #endif /* CONFIG_I2C_SLAVE */

-       return aspeed_i2c_master_irq(bus) ? IRQ_HANDLED : IRQ_NONE;
+       ret = aspeed_i2c_master_irq(bus);
+
+out:
+       spin_unlock(&bus->lock);
+       return ret ? IRQ_HANDLED : IRQ_NONE;
  }

  static int aspeed_i2c_master_xfer(struct i2c_adapter *adap,
--
2.17.1

Reviewed-by: Brendan Higgins <brendanhigg...@google.com>

Thanks!

Thanks Brendan!

BTW, to whom should I ask applying this patch? Should I send v2 after
adding your reviewed-by tag?

Thanks,

Jae