From e680b672a2b47748ee548229242b543a23b902c1 Mon Sep 17 00:00:00 2001 From: Alexandre Bounine Date: Tue, 22 Mar 2016 14:27:02 -0700 Subject: 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: Alexandre Bounine Reported-by: Barry Wood Tested-by: Barry Wood Cc: Matt Porter Cc: Aurelien Jacquiot Cc: Andre van Herk Cc: Barry Wood Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/rapidio/devices/tsi721_dma.c | 25 ++++++++++++++++--------- 1 file changed, 16 insertions(+), 9 deletions(-) (limited to 'drivers/rapidio') diff --git a/drivers/rapidio/devices/tsi721_dma.c b/drivers/rapidio/devices/tsi721_dma.c index 5bc9071ebcae..03637330c482 100644 --- a/drivers/rapidio/devices/tsi721_dma.c +++ b/drivers/rapidio/devices/tsi721_dma.c @@ -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 */ @@ -618,14 +619,14 @@ 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); } - - tsi721_advance_work(bdma_chan, bdma_chan->active_tx); - spin_unlock(&bdma_chan->lock); } /* Re-Enable BDMA channel interrupts */ @@ -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) -- cgit v1.2.3