FAILED: patch "[PATCH] mtd: spi-nor: fsl-quadspi: Don't let -EINVAL on the bus" failed to apply to 4.4-stable tree

PATCH [email protected] 1 participant 1 message Nov 11, 2018

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Stable branch Memory technology devices (MTD) SPI NOR

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2018-11-11 02:07 UTC #0 lore raw

The patch below does not apply to the 4.4-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

Quoted 1 line

From 000412276370a9bcfec73b3752ceefd9a927f1db Mon Sep 17 00:00:00 2001

From: Ahmad Fatoum <[email protected]>
Date: Fri, 21 Sep 2018 11:32:53 +0200
Subject: [PATCH] mtd: spi-nor: fsl-quadspi: Don't let -EINVAL on the bus

fsl_qspi_get_seqid() may return -EINVAL, but fsl_qspi_init_ahb_read() doesn't check for error codes with the result that -EINVAL could find itself signalled over the bus.

In conjunction with the LS1046A SoC's A-009283 errata ("Illegal accesses to SPI flash memory can result in a system hang") this illegal access to SPI flash memory results in a system hang if userspace attempts reading later on.

Avoid this by always checking fsl_qspi_get_seqid()'s return value and bail out otherwise.

Fixes e46ecda764dc ("mtd: spi-nor: Add Freescale QuadSPI driver")

Cc [email protected]

Signed-off-by Ahmad Fatoum <[email protected]>

Signed-off-by Boris Brezillon <[email protected]>

drivers/mtd/spi-nor/fsl-quadspi.c +10 -4

index 7d9620c7ff6c..d1ace310e7c1 100644
@@ -543,6 +543,9 @@ fsl_qspi_runcmd(struct fsl_qspi *q, u8 cmd, unsigned int addr, int len)
 
 	/* trigger the LUT now */
 	seqid = fsl_qspi_get_seqid(q, cmd);
+	if (seqid < 0)
+		return seqid;
+
 	qspi_writel(q, (seqid << QUADSPI_IPCR_SEQID_SHIFT) | len,
 			base + QUADSPI_IPCR);

@@ -671,7 +674,7 @@ static void fsl_qspi_set_map_addr(struct fsl_qspi *q)
  * causes the controller to clear the buffer, and use the sequence pointed
  * by the QUADSPI_BFGENCR[SEQID] to initiate a read from the flash.
  */
-static void fsl_qspi_init_ahb_read(struct fsl_qspi *q)
+static int fsl_qspi_init_ahb_read(struct fsl_qspi *q)
 {
 	void __iomem *base = q->iobase;
 	int seqid;

@@ -696,8 +699,13 @@ static void fsl_qspi_init_ahb_read(struct fsl_qspi *q)
 
 	/* Set the default lut sequence for AHB Read. */
 	seqid = fsl_qspi_get_seqid(q, q->nor[0].read_opcode);
+	if (seqid < 0)
+		return seqid;
+
 	qspi_writel(q, seqid << QUADSPI_BFGENCR_SEQID_SHIFT,
 		q->iobase + QUADSPI_BFGENCR);
+
+	return 0;
 }
 
 /* This function was used to prepare and enable QSPI clock */

@@ -805,9 +813,7 @@ static int fsl_qspi_nor_setup_last(struct fsl_qspi *q)
 	fsl_qspi_init_lut(q);
 
 	/* Init for AHB read */
-	fsl_qspi_init_ahb_read(q);
-
-	return 0;
+	return fsl_qspi_init_ahb_read(q);
 }
 
 static const struct of_device_id fsl_qspi_dt_ids[] = {