Messages in this thread | | | Date | Mon, 22 May 2023 10:33:27 +0200 | From | Miquel Raynal <> | Subject | Re: [PATCH] i3c: master: svc: add NACK check after start byte sent |
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Hi Clark,
xiaoning.wang@nxp.com wrote on Wed, 17 May 2023 11:30:30 +0800:
> Add NACK check after start byte is sent. > It is possible to detect early that a device is not on the bus > and avoid invalid transmissions thereafter. > > Signed-off-by: Clark Wang <xiaoning.wang@nxp.com>
Nice addition.
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
> --- > drivers/i3c/master/svc-i3c-master.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/drivers/i3c/master/svc-i3c-master.c b/drivers/i3c/master/svc-i3c-master.c > index 4edf33ed207d..0d63b732ef0c 100644 > --- a/drivers/i3c/master/svc-i3c-master.c > +++ b/drivers/i3c/master/svc-i3c-master.c > @@ -92,6 +92,7 @@ > #define SVC_I3C_MINTCLR 0x094 > #define SVC_I3C_MINTMASKED 0x098 > #define SVC_I3C_MERRWARN 0x09C > +#define SVC_I3C_MERRWARN_NACK BIT(2) > #define SVC_I3C_MDMACTRL 0x0A0 > #define SVC_I3C_MDATACTRL 0x0AC > #define SVC_I3C_MDATACTRL_FLUSHTB BIT(0) > @@ -1014,6 +1015,11 @@ static int svc_i3c_master_xfer(struct svc_i3c_master *master, > if (ret) > goto emit_stop; > > + if (readl(master->regs + SVC_I3C_MERRWARN) & SVC_I3C_MERRWARN_NACK) { > + ret = -ENXIO; > + goto emit_stop; > + } > + > if (rnw) > ret = svc_i3c_master_read(master, in, xfer_len); > else
Thanks, Miquèl
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