Messages in this thread Patch in this message | | | From | Frank Li <> | Subject | [PATCH 2/6] i3c: master: svc: fix wrong data return when IBI happen during start frame | Date | Mon, 16 Oct 2023 11:32:28 -0400 |
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┌─────┐ ┏──┐ ┏──┐ ┏──┐ ┏──┐ ┏──┐ ┏──┐ ┏──┐ ┏──┐ ┌───── SCL: ┘ └─────┛ └──┛ └──┛ └──┛ └──┛ └──┛ └──┛ └──┛ └──┘ ───┐ ┌─────┐ ┌─────┐ ┌───────────┐ SDA: └───────────────────────┘ └─────┘ └─────┘ └───── xxx╱ ╲╱ ╲╱ ╲╱ ╲╱ ╲ : xxx╲IBI ╱╲ Addr(0x0a) ╱╲ RW ╱╲NACK╱╲ S ╱
In-Band Interrupt (IBI) occurred and IBI work thread may not to be scheduled. When svc_i3c_master_priv_xfers() initiates the I3C transfer frame 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.
IBIWON check has been added in svc_i3c_master_xfer(). In case this situation occurs, a failure is now returned to the driver.
Fixes: dd3c52846d59 ("i3c: master: svc: Add Silvaco I3C master driver") Cc: stable@vger.kernel.org Signed-off-by: Frank Li <Frank.Li@nxp.com> --- drivers/i3c/master/svc-i3c-master.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+)
diff --git a/drivers/i3c/master/svc-i3c-master.c b/drivers/i3c/master/svc-i3c-master.c index ebdb3ea1af9d..0f57a5f75e39 100644 --- a/drivers/i3c/master/svc-i3c-master.c +++ b/drivers/i3c/master/svc-i3c-master.c @@ -1009,6 +1009,9 @@ 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 | @@ -1027,6 +1030,23 @@ 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 falure + * and yeild 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 -- 2.34.1
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