i3c: master: svc: Use readsb helper for reading MDB

commit c06acf7143bddaa3c0f7bedd8b99e48f6acb85c3 upstream.

The target can send the MDB byte followed by additional data bytes.
The readl on MRDATAB reads one actual byte, but the readsl advances
the destination pointer by 4 bytes. This causes the subsequent payload
to be copied to wrong position in the destination buffer.

Cc: stable@kernel.org
Fixes: dd3c52846d59 ("i3c: master: svc: Add Silvaco I3C master driver")
Signed-off-by: Stanley Chu <yschu@nuvoton.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Link: https://lore.kernel.org/r/20250318053606.3087121-3-yschu@nuvoton.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/i3c/master/svc-i3c-master.c b/drivers/i3c/master/svc-i3c-master.c
index 29440a1266b8a42c15a3688695fb77005475d020..368429a34d600967678247dac2589f5d52a83f96 100644 (file)
--- a/drivers/i3c/master/svc-i3c-master.c
+++ b/drivers/i3c/master/svc-i3c-master.c
@@ -315,7 +315,7 @@ static int svc_i3c_master_handle_ibi(struct svc_i3c_master *master,
               slot->len < SVC_I3C_FIFO_SIZE) {
                mdatactrl = readl(master->regs + SVC_I3C_MDATACTRL);
                count = SVC_I3C_MDATACTRL_RXCOUNT(mdatactrl);
-               readsl(master->regs + SVC_I3C_MRDATAB, buf, count);
+               readsb(master->regs + SVC_I3C_MRDATAB, buf, count);
                slot->len += count;
                buf += count;
        }