diff mbox series

[v2,7/7] i2c: npcm: Enable slave in eob interrupt

Message ID 20240830034640.7049-8-kfting@nuvoton.com
State Superseded
Headers show
Series [v2,1/7] i2c: npcm: restore slave addresses array length | expand

Commit Message

Tyrone Ting Aug. 30, 2024, 3:46 a.m. UTC 
From: Charles Boyer <Charles.Boyer@fii-usa.com>

Nuvoton slave enable was in user space API call master_xfer, so it is
subject to delays from the OS scheduler. If the BMC is not enabled for
slave mode in time for master to send response, then it will NAK the
address match. Then the PLDM request timeout occurs.

If the slave enable is moved to the EOB interrupt service routine, then
the BMC can be ready in slave mode by the time it needs to receive a
response.

Signed-off-by: Charles Boyer <Charles.Boyer@fii-usa.com>
Signed-off-by: Vivekanand Veeracholan <vveerach@google.com>
Signed-off-by: Tyrone Ting <kfting@nuvoton.com>
---
 drivers/i2c/busses/i2c-npcm7xx.c | 6 ++++++
 1 file changed, 6 insertions(+)

Comments

Tali Perry Sept. 8, 2024, 10:50 a.m. UTC | #1 
Reviewed-by: Tali Perry <tali.perry1@gmail.com>

On Fri, Aug 30, 2024 at 6:49 AM Tyrone Ting <warp5tw@gmail.com> wrote:
>
> From: Charles Boyer <Charles.Boyer@fii-usa.com>
>
> Nuvoton slave enable was in user space API call master_xfer, so it is
> subject to delays from the OS scheduler. If the BMC is not enabled for
> slave mode in time for master to send response, then it will NAK the
> address match. Then the PLDM request timeout occurs.
>
> If the slave enable is moved to the EOB interrupt service routine, then
> the BMC can be ready in slave mode by the time it needs to receive a
> response.
>
> Signed-off-by: Charles Boyer <Charles.Boyer@fii-usa.com>
> Signed-off-by: Vivekanand Veeracholan <vveerach@google.com>
> Signed-off-by: Tyrone Ting <kfting@nuvoton.com>
> ---
>  drivers/i2c/busses/i2c-npcm7xx.c | 6 ++++++
>  1 file changed, 6 insertions(+)
>
> diff --git a/drivers/i2c/busses/i2c-npcm7xx.c b/drivers/i2c/busses/i2c-npcm7xx.c
> index cac4ea0b69b8..5bdc1b5895ac 100644
> --- a/drivers/i2c/busses/i2c-npcm7xx.c
> +++ b/drivers/i2c/busses/i2c-npcm7xx.c
> @@ -1781,6 +1781,12 @@ static int npcm_i2c_int_master_handler(struct npcm_i2c *bus)
>             (FIELD_GET(NPCM_I2CCST3_EO_BUSY,
>                        ioread8(bus->reg + NPCM_I2CCST3)))) {
>                 npcm_i2c_irq_handle_eob(bus);
> +#if IS_ENABLED(CONFIG_I2C_SLAVE)
> +               /* reenable slave if it was enabled */
> +               if (bus->slave)
> +                       iowrite8((bus->slave->addr & 0x7F) | NPCM_I2CADDR_SAEN,
> +                                bus->reg + NPCM_I2CADDR1);
> +#endif
>                 return 0;
>         }
>
> --
> 2.34.1
>
diff mbox series

Patch

diff --git a/drivers/i2c/busses/i2c-npcm7xx.c b/drivers/i2c/busses/i2c-npcm7xx.c
index cac4ea0b69b8..5bdc1b5895ac 100644
--- a/drivers/i2c/busses/i2c-npcm7xx.c
+++ b/drivers/i2c/busses/i2c-npcm7xx.c
@@ -1781,6 +1781,12 @@  static int npcm_i2c_int_master_handler(struct npcm_i2c *bus)
 	    (FIELD_GET(NPCM_I2CCST3_EO_BUSY,
 		       ioread8(bus->reg + NPCM_I2CCST3)))) {
 		npcm_i2c_irq_handle_eob(bus);
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+		/* reenable slave if it was enabled */
+		if (bus->slave)
+			iowrite8((bus->slave->addr & 0x7F) | NPCM_I2CADDR_SAEN,
+				 bus->reg + NPCM_I2CADDR1);
+#endif
 		return 0;
 	}