Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
From:   Eddie James <eajames@linux.ibm.com>
To:     joel@jms.id.au
Cc:     jk@ozlabs.org, alistair@popple.id.au, linux-fsi@lists.ozlabs.org,
        linux-kernel@vger.kernel.org, Eddie James <eajames@linux.ibm.com>
Subject: [PATCH] fsi: scom: Reset the FSI2PIB engine for any error
Date:   Mon, 29 Mar 2021 10:13:44 -0500
Message-Id: <20210329151344.14246-1-eajames@linux.ibm.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

The error bits in the FSI2PIB status are only cleared by a reset. So
the driver needs to perform a reset after seeing any of the FSI2PIB
errors, otherwise subsequent operations will also look like failures.

Fixes: 6b293258cded ("fsi: scom: Major overhaul")
Signed-off-by: Eddie James <eajames@linux.ibm.com>
---
 drivers/fsi/fsi-scom.c | 16 +++++++++-------
 1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/drivers/fsi/fsi-scom.c b/drivers/fsi/fsi-scom.c
index b45bfab7b7f5..75d1389e2626 100644
--- a/drivers/fsi/fsi-scom.c
+++ b/drivers/fsi/fsi-scom.c
@@ -38,9 +38,10 @@
 #define SCOM_STATUS_PIB_RESP_MASK	0x00007000
 #define SCOM_STATUS_PIB_RESP_SHIFT	12
 
-#define SCOM_STATUS_ANY_ERR		(SCOM_STATUS_PROTECTION | \
-					 SCOM_STATUS_PARITY |	  \
-					 SCOM_STATUS_PIB_ABORT | \
+#define SCOM_STATUS_FSI2PIB_ERROR	(SCOM_STATUS_PROTECTION |	\
+					 SCOM_STATUS_PARITY |		\
+					 SCOM_STATUS_PIB_ABORT)
+#define SCOM_STATUS_ANY_ERR		(SCOM_STATUS_FSI2PIB_ERROR |	\
 					 SCOM_STATUS_PIB_RESP_MASK)
 /* SCOM address encodings */
 #define XSCOM_ADDR_IND_FLAG		BIT_ULL(63)
@@ -240,13 +241,14 @@ static int handle_fsi2pib_status(struct scom_device *scom, uint32_t status)
 {
 	uint32_t dummy = -1;
 
-	if (status & SCOM_STATUS_PROTECTION)
-		return -EPERM;
-	if (status & SCOM_STATUS_PARITY) {
+	if (status & SCOM_STATUS_FSI2PIB_ERROR)
 		fsi_device_write(scom->fsi_dev, SCOM_FSI2PIB_RESET_REG, &dummy,
 				 sizeof(uint32_t));
+
+	if (status & SCOM_STATUS_PROTECTION)
+		return -EPERM;
+	if (status & SCOM_STATUS_PARITY)
 		return -EIO;
-	}
 	/* Return -EBUSY on PIB abort to force a retry */
 	if (status & SCOM_STATUS_PIB_ABORT)
 		return -EBUSY;
-- 
2.27.0