From 37093b1ea600d84fbf7252baf12eedec85ae40f1 Mon Sep 17 00:00:00 2001 From: Hans Verkuil Date: Sat, 28 Jul 2007 19:45:50 -0300 Subject: V4L/DVB (6047): ivtv: Fix scatter/gather DMA timeouts It turns out that the cx23415/6 DMA engine cannot do scatter/gather DMA reliably. Every so often depending on the phase of the moon and your hardware configuration the cx2341x DMA engine simply chokes on it and you have to reboot to get it working again. This change replaced the scatter/gather DMA by single transfers at a time, where the driver is now responsible for DMA-ing each buffer. UDMA is still done using scatter/gather DMA, that will be fixed soon. Many thanks to Mark Bryars for discovering the link between scatter/gather and the DMA timeouts. Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab --- drivers/media/video/ivtv/ivtv-queue.c | 63 ++++++++++++++++++++--------------- 1 file changed, 36 insertions(+), 27 deletions(-) (limited to 'drivers/media/video/ivtv/ivtv-queue.c') diff --git a/drivers/media/video/ivtv/ivtv-queue.c b/drivers/media/video/ivtv/ivtv-queue.c index bff75aeee0a0..d9a1478ca1f7 100644 --- a/drivers/media/video/ivtv/ivtv-queue.c +++ b/drivers/media/video/ivtv/ivtv-queue.c @@ -195,7 +195,7 @@ void ivtv_flush_queues(struct ivtv_stream *s) int ivtv_stream_alloc(struct ivtv_stream *s) { struct ivtv *itv = s->itv; - int SGsize = sizeof(struct ivtv_SG_element) * s->buffers; + int SGsize = sizeof(struct ivtv_sg_element) * s->buffers; int i; if (s->buffers == 0) @@ -205,27 +205,33 @@ int ivtv_stream_alloc(struct ivtv_stream *s) s->dma != PCI_DMA_NONE ? "DMA " : "", s->name, s->buffers, s->buf_size, s->buffers * s->buf_size / 1024); - if (ivtv_might_use_pio(s)) { - s->PIOarray = (struct ivtv_SG_element *)kzalloc(SGsize, GFP_KERNEL); - if (s->PIOarray == NULL) { - IVTV_ERR("Could not allocate PIOarray for %s stream\n", s->name); - return -ENOMEM; - } + s->sg_pending = (struct ivtv_sg_element *)kzalloc(SGsize, GFP_KERNEL); + if (s->sg_pending == NULL) { + IVTV_ERR("Could not allocate sg_pending for %s stream\n", s->name); + return -ENOMEM; } + s->sg_pending_size = 0; - /* Allocate DMA SG Arrays */ - s->SGarray = (struct ivtv_SG_element *)kzalloc(SGsize, GFP_KERNEL); - if (s->SGarray == NULL) { - IVTV_ERR("Could not allocate SGarray for %s stream\n", s->name); - if (ivtv_might_use_pio(s)) { - kfree(s->PIOarray); - s->PIOarray = NULL; - } + s->sg_processing = (struct ivtv_sg_element *)kzalloc(SGsize, GFP_KERNEL); + if (s->sg_processing == NULL) { + IVTV_ERR("Could not allocate sg_processing for %s stream\n", s->name); + kfree(s->sg_pending); + s->sg_pending = NULL; + return -ENOMEM; + } + s->sg_processing_size = 0; + + s->sg_dma = (struct ivtv_sg_element *)kzalloc(sizeof(struct ivtv_sg_element), GFP_KERNEL); + if (s->sg_dma == NULL) { + IVTV_ERR("Could not allocate sg_dma for %s stream\n", s->name); + kfree(s->sg_pending); + s->sg_pending = NULL; + kfree(s->sg_processing); + s->sg_processing = NULL; return -ENOMEM; } - s->SG_length = 0; if (ivtv_might_use_dma(s)) { - s->SG_handle = pci_map_single(itv->dev, s->SGarray, SGsize, s->dma); + s->sg_handle = pci_map_single(itv->dev, s->sg_dma, sizeof(struct ivtv_sg_element), s->dma); ivtv_stream_sync_for_cpu(s); } @@ -272,16 +278,19 @@ void ivtv_stream_free(struct ivtv_stream *s) } /* Free SG Array/Lists */ - if (s->SGarray != NULL) { - if (s->SG_handle != IVTV_DMA_UNMAPPED) { - pci_unmap_single(s->itv->dev, s->SG_handle, - sizeof(struct ivtv_SG_element) * s->buffers, PCI_DMA_TODEVICE); - s->SG_handle = IVTV_DMA_UNMAPPED; + if (s->sg_dma != NULL) { + if (s->sg_handle != IVTV_DMA_UNMAPPED) { + pci_unmap_single(s->itv->dev, s->sg_handle, + sizeof(struct ivtv_sg_element), PCI_DMA_TODEVICE); + s->sg_handle = IVTV_DMA_UNMAPPED; } - kfree(s->SGarray); - kfree(s->PIOarray); - s->PIOarray = NULL; - s->SGarray = NULL; - s->SG_length = 0; + kfree(s->sg_pending); + kfree(s->sg_processing); + kfree(s->sg_dma); + s->sg_pending = NULL; + s->sg_processing = NULL; + s->sg_dma = NULL; + s->sg_pending_size = 0; + s->sg_processing_size = 0; } } -- cgit v1.2.3