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From:   Pratyush Yadav <p.yadav@ti.com>
To:     Tudor Ambarus <tudor.ambarus@microchip.com>,
        Miquel Raynal <miquel.raynal@bootlin.com>,
        Richard Weinberger <richard@nod.at>,
        Vignesh Raghavendra <vigneshr@ti.com>,
        Mark Brown <broonie@kernel.org>,
        Nicolas Ferre <nicolas.ferre@microchip.com>,
        Alexandre Belloni <alexandre.belloni@bootlin.com>,
        Ludovic Desroches <ludovic.desroches@microchip.com>,
        Matthias Brugger <matthias.bgg@gmail.com>,
        Michal Simek <michal.simek@xilinx.com>,
        <linux-mtd@lists.infradead.org>, <linux-kernel@vger.kernel.org>,
        <linux-spi@vger.kernel.org>,
        <linux-arm-kernel@lists.infradead.org>,
        <linux-mediatek@lists.infradead.org>
CC:     Pratyush Yadav <p.yadav@ti.com>, Sekhar Nori <nsekhar@ti.com>,
        Boris Brezillon <boris.brezillon@collabora.com>,
        Mason Yang <masonccyang@mxic.com.tw>
Subject: [PATCH v8 13/19] mtd: spi-nor: sfdp: do not make invalid quad enable fatal
Date:   Sat, 23 May 2020 04:10:36 +0530
Message-ID: <20200522224042.29970-14-p.yadav@ti.com>
In-Reply-To: <20200522224042.29970-1-p.yadav@ti.com>
References: <20200522224042.29970-1-p.yadav@ti.com>
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The Micron MT35XU512ABA flash does not support the quad enable bit. But
instead of programming the Quad Enable Require field to 000b ("Device
does not have a QE bit"), it is programmed to 111b ("Reserved").

While this is technically incorrect, it is not reason enough to abort
BFPT parsing. Instead, continue BFPT parsing assuming there is no quad
enable bit present.

Signed-off-by: Pratyush Yadav <p.yadav@ti.com>
---
 drivers/mtd/spi-nor/sfdp.c | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/drivers/mtd/spi-nor/sfdp.c b/drivers/mtd/spi-nor/sfdp.c
index 052cabb52df9..9fd3d8d9a127 100644
--- a/drivers/mtd/spi-nor/sfdp.c
+++ b/drivers/mtd/spi-nor/sfdp.c
@@ -576,10 +576,6 @@ static int spi_nor_parse_bfpt(struct spi_nor *nor,
 
 	/* Quad Enable Requirements. */
 	switch (bfpt.dwords[BFPT_DWORD(15)] & BFPT_DWORD15_QER_MASK) {
-	case BFPT_DWORD15_QER_NONE:
-		params->quad_enable = NULL;
-		break;
-
 	case BFPT_DWORD15_QER_SR2_BIT1_BUGGY:
 		/*
 		 * Writing only one byte to the Status Register has the
@@ -616,8 +612,10 @@ static int spi_nor_parse_bfpt(struct spi_nor *nor,
 		params->quad_enable = spi_nor_sr2_bit1_quad_enable;
 		break;
 
+	case BFPT_DWORD15_QER_NONE:
 	default:
-		return -EINVAL;
+		params->quad_enable = NULL;
+		break;
 	}
 
 	/* Stop here if JESD216 rev B. */
-- 
2.26.2