dmaengine: at_hdmac: Fix descriptor handling when issuing it to hardware

commit ba2423633ba646e1df20e30cb3cf35495c16f173 upstream.

As it was before, the descriptor was issued to the hardware without adding
it to the active (issued) list. This could result in a completion of other
descriptor, or/and in the descriptor never being completed.

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.com
Link: https://lore.kernel.org/r/20221025090306.297886-12-tudor.ambarus@microchip.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index 7f19e96..4cb768f 100644 (file)
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c
@@ -510,8 +510,11 @@ static void atc_advance_work(struct at_dma_chan *atchan)
 
        /* advance work */
        spin_lock_irqsave(&atchan->lock, flags);
-       if (!list_empty(&atchan->active_list))
-               atc_dostart(atchan, atc_first_active(atchan));
+       if (!list_empty(&atchan->active_list)) {
+               desc = atc_first_queued(atchan);
+               list_move_tail(&desc->desc_node, &atchan->active_list);
+               atc_dostart(atchan, desc);
+       }
        spin_unlock_irqrestore(&atchan->lock, flags);
 }
 
@@ -523,6 +526,7 @@ static void atc_advance_work(struct at_dma_chan *atchan)
 static void atc_handle_error(struct at_dma_chan *atchan)
 {
        struct at_desc *bad_desc;
+       struct at_desc *desc;
        struct at_desc *child;
        unsigned long flags;
 
@@ -540,8 +544,11 @@ static void atc_handle_error(struct at_dma_chan *atchan)
        list_splice_init(&atchan->queue, atchan->active_list.prev);
 
        /* Try to restart the controller */
-       if (!list_empty(&atchan->active_list))
-               atc_dostart(atchan, atc_first_active(atchan));
+       if (!list_empty(&atchan->active_list)) {
+               desc = atc_first_queued(atchan);
+               list_move_tail(&desc->desc_node, &atchan->active_list);
+               atc_dostart(atchan, desc);
+       }
 
        /*
         * KERN_CRITICAL may seem harsh, but since this only happens