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From: Manikanta Guntupalli <manikanta.guntupalli@xilinx.com>
To: <michal.simek@xilinx.com>, <michal.simek@amd.com>,
	<linux-arm-kernel@lists.infradead.org>,
	<linux-i2c@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
	<git@amd.com>
Cc: Raviteja Narayanam <raviteja.narayanam@xilinx.com>,
	Manikanta Guntupalli <manikanta.guntupalli@xilinx.com>
Subject: [PATCH 02/12] i2c: xiic: Enter standard mode only for > 255 byte read transfers
Date: Fri, 24 Jun 2022 17:35:17 +0530	[thread overview]
Message-ID: <1656072327-13628-3-git-send-email-manikanta.guntupalli@xilinx.com> (raw)
In-Reply-To: <1656072327-13628-1-git-send-email-manikanta.guntupalli@xilinx.com>

From: Raviteja Narayanam <raviteja.narayanam@xilinx.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@xilinx.com>
Signed-off-by: Manikanta Guntupalli <manikanta.guntupalli@xilinx.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


  parent reply	other threads:[~2022-06-24 12:06 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-06-24 12:05 [PATCH 00/12] i2c: xiic: Added Standard mode and SMBus Manikanta Guntupalli
2022-06-24 12:05 ` [PATCH 01/12] i2c: xiic: Add standard mode support for > 255 byte read transfers Manikanta Guntupalli
2022-06-29 12:18   ` Krzysztof Adamski
2022-07-13  7:54     ` Guntupalli, Manikanta
2022-07-20 10:26       ` Krzysztof Adamski
2022-07-26 10:35         ` Guntupalli, Manikanta
2022-06-24 12:05 ` Manikanta Guntupalli [this message]
2022-06-29 12:21   ` [PATCH 02/12] i2c: xiic: Enter standard mode only " Krzysztof Adamski
2022-06-30  8:06     ` Guntupalli, Manikanta
2022-06-24 12:05 ` [PATCH 03/12] i2c: xiic: Fix Rx and Tx paths in standard mode repeated start Manikanta Guntupalli
2022-06-24 12:05 ` [PATCH 04/12] i2c: xiic: Add wait for FIFO empty in send_tx Manikanta Guntupalli
2022-06-24 12:05 ` [PATCH 05/12] i2c: xiic: Use 'nmsgs' variable instead of repeated_start Manikanta Guntupalli
2022-06-24 12:05 ` [PATCH 06/12] i2c: xiic: Add smbus_block_read functionality Manikanta Guntupalli
2022-06-29 12:25   ` Krzysztof Adamski
2022-06-24 12:05 ` [PATCH 07/12] i2c: xiic: Switch to Xiic standard mode for i2c-read Manikanta Guntupalli
2022-06-24 12:05 ` [PATCH 08/12] i2c: xiic: Remove interrupt enable/disable in Rx path Manikanta Guntupalli
2022-06-24 12:05 ` [PATCH 09/12] dt-bindings: i2c: xiic: Add 'xlnx,axi-iic-2.1' to compatible Manikanta Guntupalli
2022-06-24 12:05 ` [PATCH 10/12] i2c: xiic: Update compatible with new IP version Manikanta Guntupalli
2022-06-24 12:05 ` [PATCH 11/12] i2c: xiic: Add SCL frequency configuration support Manikanta Guntupalli
2022-06-24 12:05 ` [PATCH 12/12] i2c: xiic: Correct the BNB interrupt enable sequence Manikanta Guntupalli
2022-06-29 13:13   ` Krzysztof Adamski
2022-07-13  8:02     ` Guntupalli, Manikanta

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