From: Vladimir Zapolskiy <vladimir_zapols...@mentor.com>
The change controls module users counter, which prevents to get
accidental oops on module unload while it is in use by mtd subsystem:
% dd if=/dev/mtd0 of=/dev/null &
% rmmod m25p80
Removing MTD device #0 (spi32766.0) with use count 1
Unable to handle kernel paging request at virtual address 7f4fb7f8
pgd = bd094000
[7f4fb7f8] *pgd=4cb66811, *pte=00000000, *ppte=00000000
Internal error: Oops: 80000007 [#1] PREEMPT SMP ARM
Signed-off-by: Vladimir Zapolskiy <vladimir_zapols...@mentor.com>
Signed-off-by: Sandeep Jain <sandeep_j...@mentor.com>
---
drivers/mtd/devices/m25p80.c | 15 +++++++++++++++
1 file changed, 15 insertions(+)
diff --git a/drivers/mtd/devices/m25p80.c b/drivers/mtd/devices/m25p80.c
index 9cf7fcd..2eb1530 100644
--- a/drivers/mtd/devices/m25p80.c
+++ b/drivers/mtd/devices/m25p80.c
@@ -185,6 +185,19 @@ static ssize_t m25p80_read(struct spi_nor *nor, loff_t
from, size_t len,
return ret;
}
+static void m25p80_put(struct mtd_info *mtd)
+{
+ module_put(THIS_MODULE);
+}
+
+static int m25p80_get(struct mtd_info *mtd)
+{
+ if (!try_module_get(THIS_MODULE))
+ return -ENODEV;
+
+ return 0;
+}
+
/*
* board specific setup should have ensured the SPI clock used here
* matches what the READ command supports, at least until this driver
@@ -212,6 +225,8 @@ static int m25p_probe(struct spi_device *spi)
nor->write = m25p80_write;
nor->write_reg = m25p80_write_reg;
nor->read_reg = m25p80_read_reg;
+ nor->mtd._put_device = m25p80_put;
+ nor->mtd._get_device = m25p80_get;
nor->dev = &spi->dev;
spi_nor_set_flash_node(nor, spi->dev.of_node);
--
1.7.9.5
