linux-kernel - [PATCH] mtd: spi-nor: intel-spi: Do not try to make the SPI flash chip writable

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Date:   Tue,  4 Aug 2020 10:58:17 -0300
From:   Daniel Gutson <daniel.gutson@...ypsium.com>
To:     Tudor Ambarus <tudor.ambarus@...rochip.com>,
        Miquel Raynal <miquel.raynal@...tlin.com>,
        Richard Weinberger <richard@....at>,
        Vignesh Raghavendra <vigneshr@...com>,
        Mika Westerberg <mika.westerberg@...ux.intel.com>,
        Boris Brezillon <bbrezillon@...nel.org>,
        Daniel Gutson <daniel.gutson@...ypsium.com>,
        linux-mtd@...ts.infradead.org, linux-kernel@...r.kernel.org,
        Alex Bazhaniuk <alex@...ypsium.com>,
        Richard Hughes <hughsient@...il.com>
Cc:     Arnd Bergmann <arnd@...db.de>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Subject: [PATCH] mtd: spi-nor: intel-spi: Do not try to make the SPI flash chip writable

Currently, the intel-spi-pci driver tries to unconditionally set
the SPI chip writeable. After discussing in the LKML, the original
author decided that it was better  to remove the attempt.

Context, the intel-spi has a module argument that controls
whether the driver attempts to turn the SPI flash chip writeable.
The default value is FALSE (don't try to make it writeable).
However, this flag applies only for a number of devices, coming from the
platform driver, whereas the devices detected through the PCI driver
(intel-spi-pci) are not subject to this check since the configuration
takes place in intel-spi-pci which doesn't have an argument.

This patch removes the code that attempts to turn the SPI chip writeable.

Signed-off-by: Daniel Gutson <daniel.gutson@...ypsium.com>
---
 drivers/mtd/spi-nor/controllers/intel-spi-pci.c | 7 +------
 1 file changed, 1 insertion(+), 6 deletions(-)

diff --git a/drivers/mtd/spi-nor/controllers/intel-spi-pci.c b/drivers/mtd/spi-nor/controllers/intel-spi-pci.c
index 81329f680bec..2b071da804e7 100644
--- a/drivers/mtd/spi-nor/controllers/intel-spi-pci.c
+++ b/drivers/mtd/spi-nor/controllers/intel-spi-pci.c
@@ -41,14 +41,9 @@ static int intel_spi_pci_probe(struct pci_dev *pdev,
 	if (!info)
 		return -ENOMEM;
 
-	/* Try to make the chip read/write */
 	pci_read_config_dword(pdev, BCR, &bcr);
-	if (!(bcr & BCR_WPD)) {
-		bcr |= BCR_WPD;
-		pci_write_config_dword(pdev, BCR, bcr);
-		pci_read_config_dword(pdev, BCR, &bcr);
-	}
 	info->writeable = !!(bcr & BCR_WPD);
+	dev_dbg(&pdev->dev, "device is writeable: %d\n", (int)info->writeable);
 
 	ispi = intel_spi_probe(&pdev->dev, &pdev->resource[0], info);
 	if (IS_ERR(ispi))
-- 
2.25.1