When we get an interrupt from the hardware, the first thing the driver does
is tell the device to mask off the interrupt line. Unfortunately this
involves a SPI transaction in interrupt context. Some (most?) SPI
controllers perform the transfer asynchronously and try to sleep.
This is bad, and triggers a BUG().
So, work around this by using adding a hwbus hook for the cw1200 driver
core to call. The cw1200_spi driver translates this into
irq_disable()/irq_enable() calls instead, which can safely be called in
interrupt context.
Apparently the platforms I used to develop the cw1200_spi driver used
synchronous spi_sync() implementations, which is why this didn't surface
until now.
Many thanks to Dave Sizeburns for the inital bug report and his services
as a tester.
Signed-off-by: Solomon Peachy <pizza@shaftnet.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This is only really useful for people who are bringing up new hardware
designs and have access to the proprietary vendor tools that interface
with this mode.
It'll live out of tree until it's rewritten to use a less kludgy interface.
Signed-off-by: Solomon Peachy <pizza@shaftnet.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This avoids problems when building on SPARC targets due to the driver
calling the bus abstraction layer 'sbus'. Not that any SBUS-sporting
SPARC targets are likely to have an SDIO controller, but this is the
correct thing to do.
See http://kisskb.ellerman.id.au/kisskb/buildresult/8846508/
Signed-off-by: Solomon Peachy <pizza@shaftnet.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
