From: Tudor Ambarus tudor.ambarus@microchip.com
commit 7176a6a8982d311e50a7c1168868d26e65bbba19 upstream.
tx_submit is supposed to push the current transaction descriptor to a pending queue, waiting for issue_pending() to be called. issue_pending() must start the transfer, not tx_submit(), thus remove atc_dostart() from atc_tx_submit(). Clients of at_xdmac that assume that tx_submit() starts the transfer must be updated and call dma_async_issue_pending() if they miss to call it. The vdbg print was moved to after the lock is released. It is desirable to do the prints without the lock held if possible, and because the if statement disappears there's no reason why to do the print while holding the lock.
Fixes: dc78baa2b90b ("dmaengine: at_hdmac: new driver for the Atmel AHB DMA Controller") Reported-by: Peter Rosin peda@axentia.se Signed-off-by: Tudor Ambarus tudor.ambarus@microchip.com Cc: stable@vger.kernel.org Link: https://lore.kernel.org/lkml/13c6c9a2-6db5-c3bf-349b-4c127ad3496a@axentia.se... Acked-by: Nicolas Ferre nicolas.ferre@microchip.com Link: https://lore.kernel.org/r/20221025090306.297886-1-tudor.ambarus@microchip.co... Link: https://lore.kernel.org/r/20221025090306.297886-3-tudor.ambarus@microchip.co... Signed-off-by: Vinod Koul vkoul@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/dma/at_hdmac.c | 14 +++----------- 1 file changed, 3 insertions(+), 11 deletions(-)
--- a/drivers/dma/at_hdmac.c +++ b/drivers/dma/at_hdmac.c @@ -674,19 +674,11 @@ static dma_cookie_t atc_tx_submit(struct spin_lock_irqsave(&atchan->lock, flags); cookie = dma_cookie_assign(tx);
- if (list_empty(&atchan->active_list)) { - dev_vdbg(chan2dev(tx->chan), "tx_submit: started %u\n", - desc->txd.cookie); - atc_dostart(atchan, desc); - list_add_tail(&desc->desc_node, &atchan->active_list); - } else { - dev_vdbg(chan2dev(tx->chan), "tx_submit: queued %u\n", - desc->txd.cookie); - list_add_tail(&desc->desc_node, &atchan->queue); - } - + list_add_tail(&desc->desc_node, &atchan->queue); spin_unlock_irqrestore(&atchan->lock, flags);
+ dev_vdbg(chan2dev(tx->chan), "tx_submit: queued %u\n", + desc->txd.cookie); return cookie; }