linux-kernel - [PATCH 02/12] i2c: xiic: Enter standard mode only for

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Message-ID: <1656072327-13628-3-git-send-email-manikanta.guntupalli@xilinx.com>
Date:   Fri, 24 Jun 2022 17:35:17 +0530
From:   Manikanta Guntupalli <manikanta.guntupalli@...inx.com>
To:     <michal.simek@...inx.com>, <michal.simek@....com>,
        <linux-arm-kernel@...ts.infradead.org>,
        <linux-i2c@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
        <git@....com>
CC:     Raviteja Narayanam <raviteja.narayanam@...inx.com>,
        Manikanta Guntupalli <manikanta.guntupalli@...inx.com>
Subject: [PATCH 02/12] i2c: xiic: Enter standard mode only for > 255 byte read transfers

From: Raviteja Narayanam <raviteja.narayanam@...inx.com>

To maintain backward compatibility the default transfer mode is dynamic
mode. Enter standard mode only when the size of read transfer is > 255
bytes.

Signed-off-by: Raviteja Narayanam <raviteja.narayanam@...inx.com>
Signed-off-by: Manikanta Guntupalli <manikanta.guntupalli@...inx.com>
---
 drivers/i2c/busses/i2c-xiic.c | 29 +++++++----------------------
 1 file changed, 7 insertions(+), 22 deletions(-)

diff --git a/drivers/i2c/busses/i2c-xiic.c b/drivers/i2c/busses/i2c-xiic.c
index fb2443623844..c8b68176427c 100644
--- a/drivers/i2c/busses/i2c-xiic.c
+++ b/drivers/i2c/busses/i2c-xiic.c
@@ -904,7 +904,7 @@ static int xiic_start_xfer(struct xiic_i2c *i2c, struct i2c_msg *msgs, int num)
 static int xiic_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
 {
 	struct xiic_i2c *i2c = i2c_get_adapdata(adap);
-	int err;
+	int err, count;
 
 	dev_dbg(adap->dev.parent, "%s entry SR: 0x%x\n", __func__,
 		xiic_getreg8(i2c, XIIC_SR_REG_OFFSET));
@@ -916,27 +916,12 @@ static int xiic_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
 	/* Decide standard mode or Dynamic mode */
 	i2c->dynamic = true;
 
-	/*
-	 * If number of messages is 1 and read length is > 255 bytes,
-	 * enter standard mode
-	 */
-
-	if (i2c->nmsgs == 1 && (i2c->tx_msg->flags & I2C_M_RD) &&
-	    i2c->tx_msg->len > MAX_READ_LENGTH_DYNAMIC) {
-		i2c->dynamic = false;
-	} else if (i2c->nmsgs > 1) {
-		int count;
-
-		/*
-		 * If number of messages is more than 1 and one of them is
-		 * a read message, enter standard mode. Since repeated start
-		 * operation in dynamic mode read is not happenning
-		 */
-		for (count = 0; count < i2c->nmsgs; count++) {
-			if (i2c->tx_msg[count].flags & I2C_M_RD) {
-				i2c->dynamic = false;
-				break;
-			}
+	/* Enter standard mode only when read length is > 255 bytes */
+	for (count = 0; count < i2c->nmsgs; count++) {
+		if ((i2c->tx_msg[count].flags & I2C_M_RD) &&
+		    i2c->tx_msg[count].len > MAX_READ_LENGTH_DYNAMIC) {
+			i2c->dynamic = false;
+			break;
 		}
 	}
 
-- 
2.25.1