Fix a potential NULL dereference bug during
error handling in p54spi_probe.

This bug was discovered by smatch:
(http://repo.or.cz/w/smatch.git).
Signed-off-by: NDan Carpenter <error27@gmail.com>
Signed-off-by: NChristian Lamparter <chunkeey@web.de>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Drop test for FW_STATE_RESET in p54spi_work as fw_state
is never assigned this value.
Signed-off-by: NRoel Kluin <roel.kluin@gmail.com>
Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Under high load first data word, read after available data size
is sometimes lost in p54spi_rx. It seems to depend on frequency
of interrupts and latency of data read request relatively to
'data available' interrupt. The worst consequence of this bug
is loss of packet transmission acknowledgement, which in turn
causes overflow of tx queues and permanent link loss.

Read data size and first data word in one SPI transaction.
No packets from LMAC should have length less than 1 word,
so this shouldn't interfere with the next read transaction.

Also call p54spi_sleep if p54spi_wake succeeded.
Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Put chip into sleep state, once it's been awaken.
Also, propagate error code to the caller.
Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Return whether wakeup operation succeeded.
Make use of this return value.
Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

When SPI write of odd length is requested, p54spi_write splits it
into two parts: one for all data, except the last byte, and one
for last byte and padding byte. Unfortunately, the length of
first part is not amended. It works because all meaningful bytes
have proper value and the last byte of odd length SPI write
transaction is ignored.

p54spi_work has dummy HOST_INTERRUPTS register read at the end.
Drop it, as its result is not used and it has no side effects.
Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Host is not allowed to modify DMA_WRITE_CTRL register
if bit HOST_ALLOWED in it is not set. Wait for HOST_ALLOWED first.

Also get rid of timeout in p54spi_wait_bit as it's been playing
a role of workaround for such an incorrect register access.
Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

p54spi_wakeup and p54spi_tx_frame used busy-waiting loop
to poll for 'ready' bits in SPI_ADRS_HOST_INTERRUPTS register.
With this change in place 'WR_READY timeout' messages do not
show anymore.
Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>
Acked-by: NChristian Lamparter <chunkeey@web.de>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Firmware may insert up to 4 padding bytes after the lmac header,
but it does not amend the size of SPI data transfer.
Such packets has correct data size in header, thus referencing
past the end of allocated skb. Put extra 4 bytes to the end of the
received skb to compensate for this case.
Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>
Acked-by: NChristian Lamparter <chunkeey@web.de>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

p54spi_tx_frame wasn't waiting for HOST_ALLOWED in SPI_ADRS_DMA_WRITE_CTRL.
This resulted in frequent 'WR_READY timeout' on beacon resubmission.

Also don't free skb on error path, as it gets freed on p54spi_wq_tx.
Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>
Acked-by: NChristian Lamparter <chunkeey@web.de>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Instead of firmware itself p54_upload_firmware was sending to the device
content of struct firmware and the following random garbage.

Notice '&' before priv->firmware->data at p54spi_spi_write.
But simple removing of '&' sign triggered BUG_ON at dma_cache_maint.
Thus kmemdup - kfree workaround.
Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>
Signed-off-by: NChristian Lamparter <chunkeey@web.de>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Mask value read from SPI_ADRS_DMA_WRITE_CTRL in p54spi_wait_bit.
 Without this, 'fw_upload not allowed to DMA write' is observed at both N800 and N810.
Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>
Acked-by: NChristian Lamparter <chunkeey@web.de>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This patch fixes the following waring:
> ------------[ cut here ]------------
>WARNING: at kernel/softirq.c:138 local_bh_enable+0x54/0xbc()
>Modules linked in: p54spi
>[<c0034ff8>] (dump_stack+0x0/0x14)
>[<c005b1a4>] (warn_on_slowpath+0x0/0x68)
>[<c00604c8>] (local_bh_enable+0x0/0xbc)
>[<bf000000>] (p54spi_op_tx+0x0/0x4c [p54spi])
>[<c01a4d34>] (p54_sta_unlock+0x0/0x78)

p54spi_op_tx needs to be called from different locking contexts.
Therefore we have to protect the linked list with irqsave spinlocks.
Reported-by: NMax Filippov <jcmvbkbc@gmail.com>
Signed-off-by: NChristian Lamparter <chunkeey@web.de>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

All three drivers (p54pci, p54usb and p54spi) are implementing the
same functionality three times. So, why not put it into the shared library?!
Signed-off-by: NChristian Lamparter <chunkeey@web.de>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

On Friday 16 January 2009 20:33:43 Kalle Valo wrote:
> N800 and N810 support is not on mainline yet, for stlc45xx I decided
> to add module parameters for the gpio numbers. Here's the commit from
> stlc45xx repo:
>
> http://gitorious.org/projects/stlc45xx/repos/mainline/commits/35afc5df0027d02d49e6f5bf986dcc4deb4ee6cf

This is the same patch for p54spi.
It removes all N800/N810 specific code from p54spi, so the driver can be used on
other architectures, or configurations as well.
Signed-off-by: NChristian Lamparter <chunkeey@web.de>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This patch adds the p54spi driver.
Signed-off-by: NChristian Lamparter <chunkeey@web.de>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>