Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit e680b672 authored by Alexandre Bounine's avatar Alexandre Bounine Committed by Linus Torvalds
Browse files

rapidio/tsi721_dma: fix synchronization issues 



Fix synchronization issues found during testing using multiple DMA
transfer requests to the same channel:

 - lost MSI-X interrupt notifications
 - non-synchronized attempts to start DMA channel HW resulting in error
   message from the driver
 - cookie tracking/update race conditions resulting in incorrect DMA
   transfer status report

Signed-off-by: default avatarAlexandre Bounine <alexandre.bounine@idt.com>
Reported-by: default avatarBarry Wood <barry.wood@idt.com>
Tested-by: default avatarBarry Wood <barry.wood@idt.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Aurelien Jacquiot <a-jacquiot@ti.com>
Cc: Andre van Herk <andre.van.herk@prodrive-technologies.com>
Cc: Barry Wood <barry.wood@idt.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 83472457

drivers/rapidio/devices/tsi721_dma.c

+16 −9
Original line number Diff line number Diff line
@@ -84,7 +84,7 @@ static int tsi721_bdma_ch_init(struct tsi721_bdma_chan *bdma_chan, int bd_num) 
	 */

	bd_ptr = dma_zalloc_coherent(dev,

				(bd_num + 1) * sizeof(struct tsi721_dma_desc),

				&bd_phys, GFP_KERNEL);

				&bd_phys, GFP_ATOMIC);

	if (!bd_ptr)

		return -ENOMEM;
@@ -102,7 +102,7 @@ static int tsi721_bdma_ch_init(struct tsi721_bdma_chan *bdma_chan, int bd_num) 
	sts_size = roundup_pow_of_two(sts_size);

	sts_ptr = dma_zalloc_coherent(dev,

				     sts_size * sizeof(struct tsi721_dma_sts),

				     &sts_phys, GFP_KERNEL);

				     &sts_phys, GFP_ATOMIC);

	if (!sts_ptr) {

		/* Free space allocated for DMA descriptors */

		dma_free_coherent(dev,
@@ -297,7 +297,8 @@ static irqreturn_t tsi721_bdma_msix(int irq, void *ptr) 
{

	struct tsi721_bdma_chan *bdma_chan = ptr;



	tsi721_bdma_handler(bdma_chan);

	if (bdma_chan->active)

		tasklet_schedule(&bdma_chan->tasklet);

	return IRQ_HANDLED;

}

#endif /* CONFIG_PCI_MSI */
@@ -618,15 +619,15 @@ static void tsi721_dma_tasklet(unsigned long data) 
			}

			list_add(&desc->desc_node, &bdma_chan->free_list);

			bdma_chan->active_tx = NULL;

			tsi721_advance_work(bdma_chan, NULL);

			spin_unlock(&bdma_chan->lock);

			if (callback)

				callback(param);

			spin_lock(&bdma_chan->lock);

		}



		} else {

			tsi721_advance_work(bdma_chan, bdma_chan->active_tx);

			spin_unlock(&bdma_chan->lock);

		}

	}



	/* Re-Enable BDMA channel interrupts */

	iowrite32(TSI721_DMAC_INT_ALL, bdma_chan->regs + TSI721_DMAC_INTE);
@@ -681,7 +682,7 @@ static int tsi721_alloc_chan_resources(struct dma_chan *dchan) 


	/* Allocate queue of transaction descriptors */

	desc = kcalloc(TSI721_DMA_TX_QUEUE_SZ, sizeof(struct tsi721_tx_desc),

			GFP_KERNEL);

			GFP_ATOMIC);

	if (!desc) {

		tsi_err(&dchan->dev->device,

			"DMAC%d Failed to allocate logical descriptors",
@@ -744,7 +745,13 @@ static 
enum dma_status tsi721_tx_status(struct dma_chan *dchan, dma_cookie_t cookie,

				 struct dma_tx_state *txstate)

{

	return dma_cookie_status(dchan, cookie, txstate);

	struct tsi721_bdma_chan *bdma_chan = to_tsi721_chan(dchan);

	enum dma_status	status;



	spin_lock_bh(&bdma_chan->lock);

	status = dma_cookie_status(dchan, cookie, txstate);

	spin_unlock_bh(&bdma_chan->lock);

	return status;

}



static void tsi721_issue_pending(struct dma_chan *dchan)