Commit Graph

3 Commits

Author SHA1 Message Date
Solomon Peachy
c4fb19d21b Revert "cw1200: Don't perform SPI transfers in interrupt context"
This reverts commit aec8e88c94.

This solution turned out to cause interrupt delivery problems, and
rather than trying to fix this approach, it has been scrapped in favor
of an alternative (and far simpler) implementation.

Signed-off-by: Solomon Peachy <pizza@shaftnet.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2013-09-26 14:02:31 -04:00
Solomon Peachy
aec8e88c94 cw1200: Don't perform SPI transfers in interrupt context
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>
2013-09-09 14:40:53 -04:00
Solomon Peachy
911373cca1 cw1200: Rename 'sbus' to 'hwbus'
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>
2013-06-03 15:54:37 -04:00