linux-kernel - [PATCH] drivers/fsi/scom: Remove reset before every putscom

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Date:   Thu, 20 Jul 2017 09:55:32 -0500
From:   Eddie James <eajames@...ux.vnet.ibm.com>
To:     linux-kernel@...r.kernel.org
Cc:     gregkh@...uxfoundation.org, cbostic@...ux.vnet.ibm.com,
        joel@....id.au, jk@...abs.org, eajames@...ux.vnet.ibm.com,
        "Edward A. James" <eajames@...ibm.com>
Subject: [PATCH] drivers/fsi/scom: Remove reset before every putscom

From: "Edward A. James" <eajames@...ibm.com>

Reset causes problems for operations requiring multiple scoms (e.g. i2c
over scom). Instead, reset scom engine during probe.

Signed-off-by: Edward A. James <eajames@...ibm.com>
---
 drivers/fsi/fsi-scom.c | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/drivers/fsi/fsi-scom.c b/drivers/fsi/fsi-scom.c
index 98d062f..e13353a 100644
--- a/drivers/fsi/fsi-scom.c
+++ b/drivers/fsi/fsi-scom.c
@@ -57,12 +57,6 @@ static int put_scom(struct scom_device *scom_dev, uint64_t value,
 	int rc;
 	uint32_t data;
 
-	data = cpu_to_be32(SCOM_RESET_CMD);
-	rc = fsi_device_write(scom_dev->fsi_dev, SCOM_RESET_REG, &data,
-				sizeof(uint32_t));
-	if (rc)
-		return rc;
-
 	data = cpu_to_be32((value >> 32) & 0xffffffff);
 	rc = fsi_device_write(scom_dev->fsi_dev, SCOM_DATA0_REG, &data,
 				sizeof(uint32_t));
@@ -186,6 +180,7 @@ static loff_t scom_llseek(struct file *file, loff_t offset, int whence)
 
 static int scom_probe(struct device *dev)
 {
+	uint32_t data;
 	struct fsi_device *fsi_dev = to_fsi_dev(dev);
 	struct scom_device *scom;
 
@@ -202,6 +197,9 @@ static int scom_probe(struct device *dev)
 	scom->mdev.parent = dev;
 	list_add(&scom->link, &scom_devices);
 
+	data = cpu_to_be32(SCOM_RESET_CMD);
+	fsi_device_write(fsi_dev, SCOM_RESET_REG, &data, sizeof(uint32_t));
+
 	return misc_register(&scom->mdev);
 }
 
-- 
1.8.3.1