On Thu, Aug 21, 2025 at 03:39:00PM +0000, Sven Peter wrote:
> Right now the interrupt handler first reads all updated status registers
> and only then clears the interrupts. It's possible that a duplicate
> interrupt for a changed register or plug state comes in after the
> interrupts have been processed but before they have been cleared:
>
> * plug is inserted, TPS_REG_INT_PLUG_EVENT is set
> * TPS_REG_INT_EVENT1 is read
> * tps6598x_handle_plug_event() has run and registered the plug
> * plug is removed again, TPS_REG_INT_PLUG_EVENT is set (again)
> * TPS_REG_INT_CLEAR1 is written, TPS_REG_INT_PLUG_EVENT is cleared
>
> We then have no plug connected and no pending interrupt but the tipd
> core still thinks there is a plug. It's possible to trigger this with
> e.g. a slightly broken Type-C to USB A converter.
>
> Fix this by first clearing the interrupts and only then reading the
> updated registers.
>
> Fixes: 45188f27b3d0 ("usb: typec: tipd: Add support for Apple CD321X")
> Fixes: 0a4c005bd171 ("usb: typec: driver for TI TPS6598x USB Power Delivery controllers")
> Cc: stable@xxxxxxxxxx
> Signed-off-by: Sven Peter <sven@xxxxxxxxxx>
Reviewed-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
> ---
> drivers/usb/typec/tipd/core.c | 24 +++++++++++-------------
> 1 file changed, 11 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/usb/typec/tipd/core.c b/drivers/usb/typec/tipd/core.c
> index dcf141ada07812295a6f07e41d77f95f98116010..1c80296c3b273e24ceacb3feff432c4f6e6835cc 100644
> --- a/drivers/usb/typec/tipd/core.c
> +++ b/drivers/usb/typec/tipd/core.c
> @@ -545,24 +545,23 @@ static irqreturn_t cd321x_interrupt(int irq, void *data)
> if (!event)
> goto err_unlock;
>
> + tps6598x_write64(tps, TPS_REG_INT_CLEAR1, event);
> +
> if (!tps6598x_read_status(tps, &status))
> - goto err_clear_ints;
> + goto err_unlock;
>
> if (event & APPLE_CD_REG_INT_POWER_STATUS_UPDATE)
> if (!tps6598x_read_power_status(tps))
> - goto err_clear_ints;
> + goto err_unlock;
>
> if (event & APPLE_CD_REG_INT_DATA_STATUS_UPDATE)
> if (!tps6598x_read_data_status(tps))
> - goto err_clear_ints;
> + goto err_unlock;
>
> /* Handle plug insert or removal */
> if (event & APPLE_CD_REG_INT_PLUG_EVENT)
> tps6598x_handle_plug_event(tps, status);
>
> -err_clear_ints:
> - tps6598x_write64(tps, TPS_REG_INT_CLEAR1, event);
> -
> err_unlock:
> mutex_unlock(&tps->lock);
>
> @@ -668,25 +667,24 @@ static irqreturn_t tps6598x_interrupt(int irq, void *data)
> if (!(event1[0] | event1[1] | event2[0] | event2[1]))
> goto err_unlock;
>
> + tps6598x_block_write(tps, TPS_REG_INT_CLEAR1, event1, intev_len);
> + tps6598x_block_write(tps, TPS_REG_INT_CLEAR2, event2, intev_len);
> +
> if (!tps6598x_read_status(tps, &status))
> - goto err_clear_ints;
> + goto err_unlock;
>
> if ((event1[0] | event2[0]) & TPS_REG_INT_POWER_STATUS_UPDATE)
> if (!tps6598x_read_power_status(tps))
> - goto err_clear_ints;
> + goto err_unlock;
>
> if ((event1[0] | event2[0]) & TPS_REG_INT_DATA_STATUS_UPDATE)
> if (!tps6598x_read_data_status(tps))
> - goto err_clear_ints;
> + goto err_unlock;
>
> /* Handle plug insert or removal */
> if ((event1[0] | event2[0]) & TPS_REG_INT_PLUG_EVENT)
> tps6598x_handle_plug_event(tps, status);
>
> -err_clear_ints:
> - tps6598x_block_write(tps, TPS_REG_INT_CLEAR1, event1, intev_len);
> - tps6598x_block_write(tps, TPS_REG_INT_CLEAR2, event2, intev_len);
> -
> err_unlock:
> mutex_unlock(&tps->lock);
>
>
> --
> 2.34.1
>
--
heikki
