On Fri, 21 Sep 2018 11:32:53 +0200
Ahmad Fatoum <a.fatoum@xxxxxxxxxxxxxx> wrote:
> 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.
>
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Ahmad Fatoum <a.fatoum@xxxxxxxxxxxxxx>
Added
Fixes: e46ecda764dc ("mtd: spi-nor: Add Freescale QuadSPI driver")
and queued it to spi-nor/next.
Thanks,
Boris
> ---
> drivers/mtd/spi-nor/fsl-quadspi.c | 13 +++++++++----
> 1 file changed, 9 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/mtd/spi-nor/fsl-quadspi.c b/drivers/mtd/spi-nor/fsl-quadspi.c
> index 7d9620c7ff6c..1bb42e40c38b 100644
> --- a/drivers/mtd/spi-nor/fsl-quadspi.c
> +++ b/drivers/mtd/spi-nor/fsl-quadspi.c
> @@ -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 +699,12 @@ 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 +812,7 @@ 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[] = {
