lkml.org 
[lkml]   [2012]   [Aug]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[RFC PATCH] spi/bcm63xx: Ensure that memory is freed only after it is no longer used
Date
The call to spi_unregister_master() in the device remove function frees device
memory, and with it any device local data. However, device local data is still
accessed after the call to spi_unregister_master().

Acquire a reference to the SPI device and release it after cleanup is complete
to solve the problem.

Cc: Florian Fainelli <florian@openwrt.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
Several drivers have this problem, and I am trying to find a common fix.
This solution is modeled after the approach used in spi-txx9spi:txx9spi_remove.
The other possible fix would be to move spi_unregister_master() to the end of
bcm63xx_spi_remove(), but I am not sure if it is a good idea to clean up
before the call to spi_unregister_master().

drivers/spi/spi-bcm63xx.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/spi/spi-bcm63xx.c b/drivers/spi/spi-bcm63xx.c
index 6e25ef1..ea0aaa3 100644
--- a/drivers/spi/spi-bcm63xx.c
+++ b/drivers/spi/spi-bcm63xx.c
@@ -438,7 +438,7 @@ out:

static int __devexit bcm63xx_spi_remove(struct platform_device *pdev)
{
- struct spi_master *master = platform_get_drvdata(pdev);
+ struct spi_master *master = spi_master_get(platform_get_drvdata(pdev));
struct bcm63xx_spi *bs = spi_master_get_devdata(master);

spi_unregister_master(master);
@@ -452,6 +452,8 @@ static int __devexit bcm63xx_spi_remove(struct platform_device *pdev)

platform_set_drvdata(pdev, 0);

+ spi_master_put(master);
+
return 0;
}

--
1.7.9.7


\
 
 \ /
  Last update: 2012-08-10 23:22    [from the cache]
©2003-2011 Jasper Spaans