[PATCH v2 1/3] i2c: qcom-geni: use cancel command before abort on transfer timeout

[Praveen Talari <praveen.talari@oss.qualcomm.com>]

The GENI I2C driver currently invokes geni_se_abort_m_cmd() directly when
a transfer times out. However, the GENI hardware command cancellation
flow requires a cancel command to be issued first. An abort should only
be used as a fallback when the cancel operation itself fails to complete.

Introduce a dedicated cancel_done completion that is signaled when
M_CMD_CANCEL_EN is received. The timeout recovery path waits for cancel
completion and escalates to geni_i2c_abort_xfer() only if the cancel
command does not complete within the expected time.

Co-developed-by: Naresh Maramaina <naresh.maramaina@oss.qualcomm.com>
Signed-off-by: Naresh Maramaina <naresh.maramaina@oss.qualcomm.com>
Reviewed-by: Mukesh Kumar Savaliya <mukesh.savaliya@oss.qualcomm.com>
Signed-off-by: Praveen Talari <praveen.talari@oss.qualcomm.com>
---
 drivers/i2c/busses/i2c-qcom-geni.c | 30 ++++++++++++++++++++++++++++--
 1 file changed, 28 insertions(+), 2 deletions(-)

diff --git a/drivers/i2c/busses/i2c-qcom-geni.c b/drivers/i2c/busses/i2c-qcom-geni.c
index 96dbf04138be..15403edb355a 100644
--- a/drivers/i2c/busses/i2c-qcom-geni.c
+++ b/drivers/i2c/busses/i2c-qcom-geni.c
@@ -74,6 +74,7 @@ enum geni_i2c_err_code {
 #define PACKING_BYTES_PW	4
 
 #define ABORT_TIMEOUT		HZ
+#define CANCEL_TIMEOUT		HZ
 #define XFER_TIMEOUT		HZ
 #define RST_TIMEOUT		HZ
 
@@ -112,6 +113,7 @@ struct geni_i2c_dev {
 	int err;
 	struct i2c_adapter adap;
 	struct completion done;
+	struct completion cancel_done;
 	struct i2c_msg *cur;
 	int cur_wr;
 	int cur_rd;
@@ -361,6 +363,8 @@ static irqreturn_t geni_i2c_irq(int irq, void *dev)
 	    dm_tx_st & TX_DMA_DONE || dm_tx_st & TX_RESET_DONE ||
 	    dm_rx_st & RX_DMA_DONE || dm_rx_st & RX_RESET_DONE)
 		complete(&gi2c->done);
+	if (m_stat & M_CMD_CANCEL_EN)
+		complete(&gi2c->cancel_done);
 
 	spin_unlock(&gi2c->lock);
 
@@ -387,6 +391,27 @@ static void geni_i2c_abort_xfer(struct geni_i2c_dev *gi2c)
 		dev_err(gi2c->se.dev, "Timeout abort_m_cmd\n");
 }
 
+static void geni_i2c_cancel_xfer(struct geni_i2c_dev *gi2c)
+{
+	unsigned long time_left = msecs_to_jiffies(CANCEL_TIMEOUT);
+	unsigned long flags;
+
+	reinit_completion(&gi2c->cancel_done);
+
+	spin_lock_irqsave(&gi2c->lock, flags);
+	if (!gi2c->err)
+		geni_i2c_err(gi2c, GENI_TIMEOUT);
+	gi2c->cur = NULL;
+	geni_se_cancel_m_cmd(&gi2c->se);
+	spin_unlock_irqrestore(&gi2c->lock, flags);
+
+	time_left = wait_for_completion_timeout(&gi2c->cancel_done, time_left);
+	if (!time_left) {
+		dev_err(gi2c->se.dev, "Timeout cancel_m_cmd\n");
+		geni_i2c_abort_xfer(gi2c);
+	}
+}
+
 static void geni_i2c_rx_fsm_rst(struct geni_i2c_dev *gi2c)
 {
 	u32 val;
@@ -473,7 +498,7 @@ static int geni_i2c_rx_one_msg(struct geni_i2c_dev *gi2c, struct i2c_msg *msg,
 	cur = gi2c->cur;
 	time_left = wait_for_completion_timeout(&gi2c->done, XFER_TIMEOUT);
 	if (!time_left)
-		geni_i2c_abort_xfer(gi2c);
+		geni_i2c_cancel_xfer(gi2c);
 
 	geni_i2c_rx_msg_cleanup(gi2c, cur);
 
@@ -515,7 +540,7 @@ static int geni_i2c_tx_one_msg(struct geni_i2c_dev *gi2c, struct i2c_msg *msg,
 	cur = gi2c->cur;
 	time_left = wait_for_completion_timeout(&gi2c->done, XFER_TIMEOUT);
 	if (!time_left)
-		geni_i2c_abort_xfer(gi2c);
+		geni_i2c_cancel_xfer(gi2c);
 
 	geni_i2c_tx_msg_cleanup(gi2c, cur);
 
@@ -1107,6 +1132,7 @@ static int geni_i2c_probe(struct platform_device *pdev)
 
 	gi2c->adap.algo = &geni_i2c_algo;
 	init_completion(&gi2c->done);
+	init_completion(&gi2c->cancel_done);
 	spin_lock_init(&gi2c->lock);
 	platform_set_drvdata(pdev, gi2c);
 

-- 
2.34.1