ARM: PL08x: fix atomic_t usage and tx_submit() return value range

The last_issued variable uses an atomic type, which is only
incremented inside a protected region, and then read.  Everywhere else
only reads the value, so it isn't using atomic_t correctly, and it
doesn't even need to.  Moreover, the DMA engine code provides us with
a variable for this already - chan.cookie.  Use chan.cookie instead.

Also, avoid negative dma_cookie_t values - negative returns from
tx_submit() mean failure, yet in reality we always succeed.  Restart
from cookie 1, just like other DMA engine drivers do.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

1 files changed, 0 insertions, 1 deletions

diff --git a/include/linux/amba/pl08x.h b/include/linux/amba/pl08x.h
index 521a0f8974ac..4ae62b4684f9 100644
--- a/include/linux/amba/pl08x.h
+++ b/include/linux/amba/pl08x.h
@@ -174,7 +174,6 @@ struct pl08x_dma_chan {
         struct pl08x_channel_data *cd;
         dma_addr_t runtime_addr;
         enum dma_data_direction runtime_direction;
-        atomic_t last_issued;
         dma_cookie_t lc;
         struct list_head desc_list;
         struct pl08x_txd *at;