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author | Fabio Estevam <fabio.estevam@freescale.com> | 2015-01-13 20:14:15 -0200 |
---|---|---|
committer | Brian Norris <computersforpeace@gmail.com> | 2015-01-20 12:37:57 -0800 |
commit | cfe4af3aac3bd63e9caf548157805ca46ad7b073 (patch) | |
tree | 8432c64db6f009425799a7e09c22b2321a1b12c9 /drivers/mtd | |
parent | fcc87a95195236b0935183361a72e4a98bf577d8 (diff) | |
download | linux-cfe4af3aac3bd63e9caf548157805ca46ad7b073.tar.gz linux-cfe4af3aac3bd63e9caf548157805ca46ad7b073.tar.bz2 linux-cfe4af3aac3bd63e9caf548157805ca46ad7b073.zip |
mtd: fsl-quadspi: Fix module unbound
When removing the fsl-quadspi module and running 'cat /proc/mtd' afterwards,
we see garbage data like:
$ rmmod fsl-quadspi
$ cat /proc/mtd
dev: size erasesize name
mtd0: 00000000 00000000 "(null)"
mtd0: 00000000 00000000 "(null)"
mtd0: 00000000 00000000 "(null)"
...
mtd0: a22296c6c756e28 00000000 "(null)"
mtd0: a22296c6c756e28 3064746d "(null)"
If we continue doing multiple module load/unload operations, then it will also
lead to a kernel crash.
The reason for this is due to the wrong mtd index used in
mtd_device_unregister() in the remove function.
We need to keep the mtd unregister index aligned with the one used in the probe
function, which means we need to take into account the 'has_second_chip'
property. By doing so we can guarantee that the mtd index is the same in the
registration and unregistration functions.
With this patch applied we can load/unload the fsl-quadspi driver several times
and it will result in no crash.
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Acked-by: Huang Shijie <shijie.huang@intel.com>
Tested-by: Frank Li <Frank.Li@freescale.com>
Acked-by: Allen Xu <han.xu@freescale.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Diffstat (limited to 'drivers/mtd')
-rw-r--r-- | drivers/mtd/spi-nor/fsl-quadspi.c | 19 |
1 files changed, 13 insertions, 6 deletions
diff --git a/drivers/mtd/spi-nor/fsl-quadspi.c b/drivers/mtd/spi-nor/fsl-quadspi.c index 9d6080079a45..a46bea33580f 100644 --- a/drivers/mtd/spi-nor/fsl-quadspi.c +++ b/drivers/mtd/spi-nor/fsl-quadspi.c @@ -227,6 +227,7 @@ struct fsl_qspi { u32 nor_num; u32 clk_rate; unsigned int chip_base_addr; /* We may support two chips. */ + bool has_second_chip; }; static inline int is_vybrid_qspi(struct fsl_qspi *q) @@ -783,7 +784,6 @@ static int fsl_qspi_probe(struct platform_device *pdev) struct spi_nor *nor; struct mtd_info *mtd; int ret, i = 0; - bool has_second_chip = false; const struct of_device_id *of_id = of_match_device(fsl_qspi_dt_ids, &pdev->dev); @@ -860,14 +860,14 @@ static int fsl_qspi_probe(struct platform_device *pdev) goto irq_failed; if (of_get_property(np, "fsl,qspi-has-second-chip", NULL)) - has_second_chip = true; + q->has_second_chip = true; /* iterate the subnodes. */ for_each_available_child_of_node(dev->of_node, np) { char modalias[40]; /* skip the holes */ - if (!has_second_chip) + if (!q->has_second_chip) i *= 2; nor = &q->nor[i]; @@ -943,9 +943,12 @@ static int fsl_qspi_probe(struct platform_device *pdev) return 0; last_init_failed: - for (i = 0; i < q->nor_num; i++) + for (i = 0; i < q->nor_num; i++) { + /* skip the holes */ + if (!q->has_second_chip) + i *= 2; mtd_device_unregister(&q->mtd[i]); - + } irq_failed: clk_disable_unprepare(q->clk); clk_failed: @@ -960,8 +963,12 @@ static int fsl_qspi_remove(struct platform_device *pdev) struct fsl_qspi *q = platform_get_drvdata(pdev); int i; - for (i = 0; i < q->nor_num; i++) + for (i = 0; i < q->nor_num; i++) { + /* skip the holes */ + if (!q->has_second_chip) + i *= 2; mtd_device_unregister(&q->mtd[i]); + } /* disable the hardware */ writel(QUADSPI_MCR_MDIS_MASK, q->iobase + QUADSPI_MCR); |