[PATCH 3/5] i2c: aspeed: fix master pending state handling
Tao Ren
taoren at fb.com
Wed Oct 9 09:00:46 AEDT 2019
On 10/7/19 4:13 PM, Jae Hyun Yoo wrote:
> In case of master pending state, it should not trigger the master
> command because this H/W is sharing the same data buffer for slave
> and master operations, so this commit fixes the issue with making
> the master command triggering happen when the state goes to active
> state.
>
> Signed-off-by: Jae Hyun Yoo <jae.hyun.yoo at linux.intel.com>
> ---
> drivers/i2c/busses/i2c-aspeed.c | 9 +++++----
> 1 file changed, 5 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-aspeed.c b/drivers/i2c/busses/i2c-aspeed.c
> index fa66951b05d0..40f6cf98d32e 100644
> --- a/drivers/i2c/busses/i2c-aspeed.c
> +++ b/drivers/i2c/busses/i2c-aspeed.c
> @@ -336,18 +336,19 @@ static void aspeed_i2c_do_start(struct aspeed_i2c_bus *bus)
> struct i2c_msg *msg = &bus->msgs[bus->msgs_index];
> u8 slave_addr = i2c_8bit_addr_from_msg(msg);
>
> - bus->master_state = ASPEED_I2C_MASTER_START;
> -
> #if IS_ENABLED(CONFIG_I2C_SLAVE)
> /*
> * If it's requested in the middle of a slave session, set the master
> * state to 'pending' then H/W will continue handling this master
> * command when the bus comes back to the idle state.
> */
> - if (bus->slave_state != ASPEED_I2C_SLAVE_INACTIVE)
> + if (bus->slave_state != ASPEED_I2C_SLAVE_INACTIVE) {
> bus->master_state = ASPEED_I2C_MASTER_PENDING;
> + return;
> + }
> #endif /* CONFIG_I2C_SLAVE */
>
> + bus->master_state = ASPEED_I2C_MASTER_START;
> bus->buf_index = 0;
>
> if (msg->flags & I2C_M_RD) {
> @@ -432,7 +433,7 @@ static u32 aspeed_i2c_master_irq(struct aspeed_i2c_bus *bus, u32 irq_status)
> if (bus->slave_state != ASPEED_I2C_SLAVE_INACTIVE)
> goto out_no_complete;
>
> - bus->master_state = ASPEED_I2C_MASTER_START;
> + aspeed_i2c_do_start(bus);
> }
Shall we move the restart-master logic from master_irq to bus_irq? The reason being:
master transaction cannot be restarted when aspeed-i2c is running in slave state and
receives STOP interrupt, because aspeed_i2c_master_irq won't be called in this case.
Cheers,
Tao
More information about the Linux-aspeed
mailing list