On 14-11-23, 13:22, Thomas Pfaff wrote:
> From: Thomas Pfaff <tpfaff@xxxxxxx>
>
> In kernel 6.1, atc_advance_work and atc_handle_error are checking for the
> next dma transfer inside active list, but the descriptor is taken from the
> queue instead.
Sorry that is not how this works. Please send the patch for mainline and
add a stable tag to the patches. They will be backported to stable
kernels
Also, your patch threading is broken, they appear disjoint and not as a
series
Thanks
>
> Signed-off-by: Thomas Pfaff <tpfaff@xxxxxxx>
> ---
> diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
> index 858bd64f1313..68c1bfbefc5c 100644
> --- a/drivers/dma/at_hdmac.c
> +++ b/drivers/dma/at_hdmac.c
> @@ -490,6 +490,27 @@ atc_chain_complete(struct at_dma_chan *atchan, struct at_desc *desc)
> }
> }
>
> +/**
> + * atc_start_next - start next pending transaction if any
> + * @atchan: channel where the transaction ended
> + *
> + * Called with atchan->lock held
> + */
> +static void atc_start_next(struct at_dma_chan *atchan)
> +{
> + struct at_desc *desc = NULL;
> +
> + if (!list_empty(&atchan->active_list))
> + desc = atc_first_active(atchan);
> + else if (!list_empty(&atchan->queue)) {
> + desc = atc_first_queued(atchan);
> + list_move_tail(&desc->desc_node, &atchan->active_list);
> + }
> +
> + if (desc)
> + atc_dostart(atchan, desc);
> +}
> +
> /**
> * atc_advance_work - at the end of a transaction, move forward
> * @atchan: channel where the transaction ended
> @@ -513,11 +534,7 @@ static void atc_advance_work(struct at_dma_chan *atchan)
>
> /* advance work */
> spin_lock_irqsave(&atchan->lock, flags);
> - if (!list_empty(&atchan->active_list)) {
> - desc = atc_first_queued(atchan);
> - list_move_tail(&desc->desc_node, &atchan->active_list);
> - atc_dostart(atchan, desc);
> - }
> + atc_start_next(atchan);
> spin_unlock_irqrestore(&atchan->lock, flags);
> }
>
> @@ -529,7 +546,6 @@ 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;
>
> @@ -543,11 +559,7 @@ static void atc_handle_error(struct at_dma_chan *atchan)
> list_del_init(&bad_desc->desc_node);
>
> /* Try to restart the controller */
> - if (!list_empty(&atchan->active_list)) {
> - desc = atc_first_queued(atchan);
> - list_move_tail(&desc->desc_node, &atchan->active_list);
> - atc_dostart(atchan, desc);
> - }
> + atc_start_next(atchan);
>
> /*
> * KERN_CRITICAL may seem harsh, but since this only happens
>
--
~Vinod
