3.16.63-rc1 review patch. If anyone has any objections, please let me know.
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From: Ahmad Fatoum a.fatoum@pengutronix.de
commit 000412276370a9bcfec73b3752ceefd9a927f1db upstream.
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") Signed-off-by: Ahmad Fatoum a.fatoum@pengutronix.de Signed-off-by: Boris Brezillon boris.brezillon@bootlin.com [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings ben@decadent.org.uk --- drivers/mtd/spi-nor/fsl-quadspi.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-)
--- a/drivers/mtd/spi-nor/fsl-quadspi.c +++ b/drivers/mtd/spi-nor/fsl-quadspi.c @@ -451,6 +451,9 @@ fsl_qspi_runcmd(struct fsl_qspi *q, u8 c
/* trigger the LUT now */ seqid = fsl_qspi_get_seqid(q, cmd); + if (seqid < 0) + return seqid; + writel((seqid << QUADSPI_IPCR_SEQID_SHIFT) | len, base + QUADSPI_IPCR);
/* Wait for the interrupt. */ @@ -574,7 +577,7 @@ static void fsl_qspi_set_map_addr(struct * 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; @@ -592,8 +595,13 @@ static void fsl_qspi_init_ahb_read(struc
/* Set the default lut sequence for AHB Read. */ seqid = fsl_qspi_get_seqid(q, q->nor[0].read_opcode); + if (seqid < 0) + return seqid; + writel(seqid << QUADSPI_BFGENCR_SEQID_SHIFT, q->iobase + QUADSPI_BFGENCR); + + return 0; }
/* We use this function to do some basic init for spi_nor_scan(). */ @@ -647,9 +655,7 @@ static int fsl_qspi_nor_setup_last(struc 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 struct of_device_id fsl_qspi_dt_ids[] = {