diff mbox series

[v3,3/6] i3c: master: svc: fix ibi may not return mandatory data byte

Message ID 20231019222725.3598022-4-Frank.Li@nxp.com
State New
Headers
Series i3c: master: svc: collection of bugs fixes |

Commit Message

Frank Li Oct. 19, 2023, 10:27 p.m. UTC 
  MSTATUS[RXPEND] is only updated after the data transfer cycle started. This
creates an issue when the I3C clock is slow, and the CPU is running fast
enough that MSTATUS[RXPEND] may not be updated when the code reaches
checking point. As a result, mandatory data can be missed.

Add a wait for MSTATUS[COMPLETE] to ensure that all mandatory data is
already in FIFO. It also works without mandatory data.

Fixes: dd3c52846d59 ("i3c: master: svc: Add Silvaco I3C master driver")
Cc: stable@vger.kernel.org
Signed-off-by: Frank Li <Frank.Li@nxp.com>
---

Notes:
    Change from v2 to v3
    - update commit message and add no mandatory data in commits message
    
    Change from v1 to v2
    - update commit message
      it also works without mandatory bytes
    
    Change from v1 to v2
    - update commit message
      it also works without mandatory bytes

 drivers/i3c/master/svc-i3c-master.c | 8 ++++++++
 1 file changed, 8 insertions(+)

Comments

Miquel Raynal Oct. 20, 2023, 1:49 p.m. UTC | #1 
Hi Frank,

Frank.Li@nxp.com wrote on Thu, 19 Oct 2023 18:27:22 -0400:

> MSTATUS[RXPEND] is only updated after the data transfer cycle started. This
> creates an issue when the I3C clock is slow, and the CPU is running fast
> enough that MSTATUS[RXPEND] may not be updated when the code reaches
> checking point. As a result, mandatory data can be missed.
> 
> Add a wait for MSTATUS[COMPLETE] to ensure that all mandatory data is
> already in FIFO. It also works without mandatory data.
> 
> Fixes: dd3c52846d59 ("i3c: master: svc: Add Silvaco I3C master driver")
> Cc: stable@vger.kernel.org
> Signed-off-by: Frank Li <Frank.Li@nxp.com>

Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>

Thanks,
Miquèl
diff mbox series

Patch

diff --git a/drivers/i3c/master/svc-i3c-master.c b/drivers/i3c/master/svc-i3c-master.c
index abebef666b2bb..dd06b7c9333f1 100644
--- a/drivers/i3c/master/svc-i3c-master.c
+++ b/drivers/i3c/master/svc-i3c-master.c
@@ -332,6 +332,7 @@  static int svc_i3c_master_handle_ibi(struct svc_i3c_master *master,
 	struct i3c_ibi_slot *slot;
 	unsigned int count;
 	u32 mdatactrl;
+	int ret, val;
 	u8 *buf;
 
 	slot = i3c_generic_ibi_get_free_slot(data->ibi_pool);
@@ -341,6 +342,13 @@  static int svc_i3c_master_handle_ibi(struct svc_i3c_master *master,
 	slot->len = 0;
 	buf = slot->data;
 
+	ret = readl_relaxed_poll_timeout(master->regs + SVC_I3C_MSTATUS, val,
+						SVC_I3C_MSTATUS_COMPLETE(val), 0, 1000);
+	if (ret) {
+		dev_err(master->dev, "Timeout when polling for COMPLETE\n");
+		return ret;
+	}
+
 	while (SVC_I3C_MSTATUS_RXPEND(readl(master->regs + SVC_I3C_MSTATUS))  &&
 	       slot->len < SVC_I3C_FIFO_SIZE) {
 		mdatactrl = readl(master->regs + SVC_I3C_MDATACTRL);