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i3c: master: svc: fix wrong data return when IBI happen during start frame

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┌─────┐     ┏──┐  ┏──┐  ┏──┐  ┏──┐  ┏──┐  ┏──┐  ┏──┐  ┏──┐  ┌─────
SCL: ┘     └─────┛  └──┛  └──┛  └──┛  └──┛  └──┛  └──┛  └──┛  └──┘
     ───┐                       ┌─────┐     ┌─────┐     ┌───────────┐
SDA:    └───────────────────────┘     └─────┘     └─────┘           └─────
     xxx╱    ╲╱                                        ╲╱    ╲╱    ╲╱    ╲
   : xxx╲IBI ╱╲               Addr(0x0a)               ╱╲ RW ╱╲NACK╱╲ S  ╱

If an In-Band Interrupt (IBI) occurs and IBI work thread is not immediately
scheduled, when svc_i3c_master_priv_xfers() initiates the I3C transfer and
attempts to send address 0x7e, the target interprets it as an
IBI handler and returns the target address 0x0a.

However, svc_i3c_master_priv_xfers() does not handle this case and proceeds
with other transfers, resulting in incorrect data being returned.

Add IBIWON check in svc_i3c_master_xfer(). In case this situation occurs,
return a failure to the driver.

Fixes: dd3c52846d ("i3c: master: svc: Add Silvaco I3C master driver")
Cc:  <stable@vger.kernel.org>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Frank Li <Frank.Li@nxp.com>
Link: https://lore.kernel.org/r/20231023161658.3890811-3-Frank.Li@nxp.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
This commit is contained in:
Frank Li 2023-10-23 12:16:54 -04:00 committed by Alexandre Belloni
parent 6bf3fc2681
commit 5e5e3c92e7
1 changed files with 20 additions and 0 deletions
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20
drivers/i3c/master/svc-i3c-master.c
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@ -1011,6 +1011,9 @@ static int svc_i3c_master_xfer(struct svc_i3c_master *master,
u32 reg;
int ret;
/* clean SVC_I3C_MINT_IBIWON w1c bits */
writel(SVC_I3C_MINT_IBIWON, master->regs + SVC_I3C_MSTATUS);
writel(SVC_I3C_MCTRL_REQUEST_START_ADDR |
xfer_type |
SVC_I3C_MCTRL_IBIRESP_NACK |
@ -1029,6 +1032,23 @@ static int svc_i3c_master_xfer(struct svc_i3c_master *master,
goto emit_stop;
}
/*
* According to I3C spec ver 1.1.1, 5.1.2.2.3 Consequence of Controller Starting a Frame
* with I3C Target Address.
*
* The I3C Controller normally should start a Frame, the Address may be arbitrated, and so
* the Controller shall monitor to see whether an In-Band Interrupt request, a Controller
* Role Request (i.e., Secondary Controller requests to become the Active Controller), or
* a Hot-Join Request has been made.
*
* If missed IBIWON check, the wrong data will be return. When IBIWON happen, return failure
* and yield the above events handler.
*/
if (SVC_I3C_MSTATUS_IBIWON(reg)) {
ret = -ENXIO;
goto emit_stop;
}
if (rnw)
ret = svc_i3c_master_read(master, in, xfer_len);
else