Commit 49b472eb authored by Clark Wang's avatar Clark Wang Committed by Alexandre Belloni
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i3c: master: svc: add NACK check after start byte sent 



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: default avatarClark Wang <xiaoning.wang@nxp.com>
Reviewed-by: default avatarMiquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/r/20230517033030.3068085-3-xiaoning.wang@nxp.com


Signed-off-by: default avatarAlexandre Belloni <alexandre.belloni@bootlin.com>
parent 33beadb3

drivers/i3c/master/svc-i3c-master.c

+6 −0
Original line number Diff line number Diff line
@@ -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