Re: [PATCH v1 3/3] i3c: master: svc: fix npcm845 invalid slvstart event

Frank Li
2025-02-19T21:18:39Z

On Wed, Feb 19, 2025 at 09:10:19AM +0800, Stanley Chu wrote:
> I3C HW may generate an invalid SlvStart event when emitting a STOP.
> If it is a true SlvStart, the MSTATUS state should be SLVREQ.
> Check the MSTATUS state to ignore the false event.
>
> Signed-off-by: Stanley Chu <yschu@nuvoton.com>
> ---
> drivers/i3c/master/svc-i3c-master.c | 15 ++++++++++++++-
> 1 file changed, 14 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/i3c/master/svc-i3c-master.c b/drivers/i3c/master/svc-i3c-master.c
> index 22cb1f1c1fdc..14cedcb81c52 100644
> --- a/drivers/i3c/master/svc-i3c-master.c
> +++ b/drivers/i3c/master/svc-i3c-master.c
> @@ -59,6 +59,7 @@
> #define SVC_I3C_MSTATUS_STATE(x) FIELD_GET(GENMASK(2, 0), (x))
> #define SVC_I3C_MSTATUS_STATE_DAA(x) (SVC_I3C_MSTATUS_STATE(x) == 5)
> #define SVC_I3C_MSTATUS_STATE_IDLE(x) (SVC_I3C_MSTATUS_STATE(x) == 0)
> +#define SVC_I3C_MSTATUS_STATE_SLVREQ(x) (SVC_I3C_MSTATUS_STATE(x) == 1)
> #define SVC_I3C_MSTATUS_BETWEEN(x) FIELD_GET(BIT(4), (x))
> #define SVC_I3C_MSTATUS_NACKED(x) FIELD_GET(BIT(5), (x))
> #define SVC_I3C_MSTATUS_IBITYPE(x) FIELD_GET(GENMASK(7, 6), (x))
> @@ -143,6 +144,12 @@
> * Fill the FIFO in advance to prevent FIFO from becoming empty.
> */
> #define SVC_I3C_QUIRK_FIFO_EMPTY BIT(0)
> +/*
> + * SVC_I3C_QUIRK_FLASE_SLVSTART:
> + * I3C HW may generate an invalid SlvStart event when emitting a STOP.
> + * If it is a true SlvStart, the MSTATUS state should be SLVREQ.
> + */
> +#define SVC_I3C_QUIRK_FALSE_SLVSTART BIT(1)
>
> struct svc_i3c_cmd {
> u8 addr;
> @@ -576,6 +583,11 @@ static irqreturn_t svc_i3c_master_irq_handler(int irq, void *dev_id)
> /* Clear the interrupt status */
> writel(SVC_I3C_MINT_SLVSTART, master->regs + SVC_I3C_MSTATUS);
>
> + /* Ignore the false event */
> + if ((master->quirks & SVC_I3C_QUIRK_FIFO_EMPTY) &&

You should check SVC_I3C_QUIRK_FALSE_SLVSTART, not SVC_I3C_QUIRK_FIFO_EMPTY

Frank
> + !SVC_I3C_MSTATUS_STATE_SLVREQ(active))
> + return IRQ_HANDLED;
> +
> svc_i3c_master_disable_interrupts(master);
>
> /* Handle the interrupt in a non atomic context */
> @@ -1915,7 +1927,8 @@ static int svc_i3c_master_probe(struct platform_device *pdev)
> svc_i3c_master_reset(master);
>
> if (device_is_compatible(master->dev, "nuvoton,npcm845-i3c"))
> - master->quirks = SVC_I3C_QUIRK_FIFO_EMPTY;
> + master->quirks = SVC_I3C_QUIRK_FIFO_EMPTY |
> + SVC_I3C_QUIRK_FALSE_SLVSTART;
>
> /* Register the master */
> ret = i3c_master_register(&master->base, &pdev->dev,
> --
> 2.34.1