path: root/kernel
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authorDavid Brownell <dbrownell@users.sourceforge.net>2008-08-15 00:40:44 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2008-08-15 08:35:44 -0700
commite48880e02e7e7ead9daa47fe3a20486f550668d3 (patch)
treee46cb1788109caf59fcb77453dffd43fec6e305e /kernel
parent7d455e0030eeab820773e7786605be4d9e56a04b (diff)
spi: bugfix spi_add_device() with duplicate chipselects
When reviewing a recent patch I noticed a potential trouble spot in the registration of new SPI devices. The SPI master driver is told to set the device up before adding it to the driver model, so that it's always properly set up when probe() is called. (This is important, because in the case of inverted chipselects, this device can make the bus misbehave until it's properly deselected. It's got to be set up even if no driver binds to the device.) The trouble spot is that it doesn't first verify that no other device has been added using that chipselect. If such a device has been added, its configuration gets trashed. (Fortunately this has not been a common error!) The fix here adds an explicit check, and a mutex to protect the relevant critical region. [akpm@linux-foundation.org: make the lock local to spi_add_device()] Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel')
0 files changed, 0 insertions, 0 deletions

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