This patch adds an error recovery mechanism on TX path.
The intention is to bring back the device to some known state
whenever TX sees -110 (-ETIMEOUT) on copying the data to the HW FIFO.
The TX failure could mean a device bus stuck or function stuck, so
the current error recovery implementation is to trigger a bus reset
and expect this can bring back the device.
Since the TX work is done in a thread context, there may be a queue of TX works
already that all hit the -ETIMEOUT error condition because the device has
somewhat stuck already. We don't want any consecutive bus resets simply because
multiple TX works in the queue all hit the same device erratum, the flag
"error_recovery" is introduced to denote if we are ready for taking any
error recovery. See @error_recovery doc in i2400m.h.
Signed-off-by: Cindy H Kao <cindy.h.kao@intel.com>
The race condition happens when the TX queue is accessed by
the TX work while the same TX queue is being destroyed because
a bus reset is triggered either by debugfs entry or simply
by failing waking up the device from WiMAX IDLE mode.
This fix is to prevent the TX queue from being accessed by
multiple threads
Signed-off-by: Cindy H Kao <cindy.h.kao@intel.com>
All the entry points into the TX module should check if the device has
been torn down. Otherwise, when the device resets or shuts down, there
are windows when a call to i2400m_tx*() will oops the system.
For that, make i2400m_tx_release() set i2400m->tx_buf to NULL under
the tx_lock. Then, any entry point [i2400m_tx(), _tx_msg_sent(),
_tx_msg_get()] will check for i2400m->tx_buf to be NULL and exit
gracefully.
Signed-off-by: Inaky Perez-Gonzalez <inaky@linux.intel.com>
Implements the backend so that the generic driver can TX/RX to/from
the SDIO device.
For RX, when data is ready the SDIO IRQ is fired and that will
allocate an skb, put all the data there and then pass it to the
generic driver RX code for processing and delivery.
TX, when kicked by the generic driver, will schedule work on a
driver-specific workqueue that pulls data from the TX FIFO and sends
it to the device until it drains it.
Thread contexts are needed as SDIO functions are blocking.
Signed-off-by: Inaky Perez-Gonzalez <inaky@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Cindy H Kao