[PATCH v2] EDAC/altera: Handle OCRAM ECC enable after warm reset

niravkumarlaxmidas.rabara@altera.com posted 1 patch an hour ago
drivers/edac/altera_edac.c | 18 +++++++++++++++---
1 file changed, 15 insertions(+), 3 deletions(-)
[PATCH v2] EDAC/altera: Handle OCRAM ECC enable after warm reset
Posted by niravkumarlaxmidas.rabara@altera.com an hour ago
From: Niravkumar L Rabara <niravkumarlaxmidas.rabara@altera.com>

The OCRAM ECC is always enabled either by the BootROM or by the Secure
Device Manager (SDM) during a power-on reset on SoCFPGA.

However, during a warm reset, the OCRAM content is retained to preserve
data, while the control and status registers are reset to their default
values. As a result, ECC must be explicitly re-enabled after a warm reset.

Fixes: 17e47dc6db4f ("EDAC/altera: Add Stratix10 OCRAM ECC support")
Cc: stable@vger.kernel.org
Signed-off-by: Niravkumar L Rabara <niravkumarlaxmidas.rabara@altera.com>
Acked-by: Dinh Nguyen <dinguyen@kernel.org>
---

v2 changes:
 - Add Fixes and Cc tags
 - Retains Acked-by from v1 patch

v1 link:
https://lore.kernel.org/all/20251103140920.1060643-1-niravkumarlaxmidas.rabara@altera.com/

 drivers/edac/altera_edac.c | 18 +++++++++++++++---
 1 file changed, 15 insertions(+), 3 deletions(-)

diff --git a/drivers/edac/altera_edac.c b/drivers/edac/altera_edac.c
index 103b2c2eba2a..a776d61027f2 100644
--- a/drivers/edac/altera_edac.c
+++ b/drivers/edac/altera_edac.c
@@ -1184,10 +1184,22 @@ altr_check_ocram_deps_init(struct altr_edac_device_dev *device)
 	if (ret)
 		return ret;
 
-	/* Verify OCRAM has been initialized */
+	/*
+	 * Verify that OCRAM has been initialized.
+	 * During a warm reset, OCRAM contents are retained, but the control
+	 * and status registers are reset to their default values. Therefore,
+	 * ECC must be explicitly re-enabled in the control register.
+	 * Error condition: if INITCOMPLETEA is clear and ECC_EN is already set.
+	 */
 	if (!ecc_test_bits(ALTR_A10_ECC_INITCOMPLETEA,
-			   (base + ALTR_A10_ECC_INITSTAT_OFST)))
-		return -ENODEV;
+			   (base + ALTR_A10_ECC_INITSTAT_OFST))) {
+		if (!ecc_test_bits(ALTR_A10_ECC_EN,
+				   (base + ALTR_A10_ECC_CTRL_OFST)))
+			ecc_set_bits(ALTR_A10_ECC_EN,
+				     (base + ALTR_A10_ECC_CTRL_OFST));
+		else
+			return -ENODEV;
+	}
 
 	/* Enable IRQ on Single Bit Error */
 	writel(ALTR_A10_ECC_SERRINTEN, (base + ALTR_A10_ECC_ERRINTENS_OFST));
-- 
2.25.1