[PATCH] Re: More than 2Gb problem (dvb related) ?

[Jon Burgess]

On Fri, 2007-04-27 at 18:06 -0400, Lee Revell wrote:
> On 4/27/07, Jon Burgess <jburgess777@xxxxxxxxxxxxxx> wrote:
> > Interesting - I see similar symptoms after upgrading my PC:
> > * old PC was AMD Athlon 64 3000 w/ 2GB of RAM which had no issues
> > * new PC is a Intel Core 2 Duo w/ 4GB of RAM and fails in the way you
> > describe.
> 
> Driver using an incorrect DMA mask?
> 
> Lee

It appears the problem is that the driver is using streamed PCI and
needs to explicitly sync the data otherwise it breaks when the SWIOTLB
is in use. A call to pci_unmap_sg() was missing too.

This patch is against the current v4l-dvb HG tree.

I've only tested the change with a budget-ci card.

	Jon

Signed-off-by: Jon Burgess <jburgess777@xxxxxxxxxxxxxx>
diff -r a8b2a0738f4e linux/drivers/media/common/saa7146_core.c
--- a/linux/drivers/media/common/saa7146_core.c	Thu Apr 19 17:07:37 2007 -0300
+++ b/linux/drivers/media/common/saa7146_core.c	Sat Apr 28 17:44:38 2007 +0100
@@ -152,6 +152,7 @@ char *saa7146_vmalloc_build_pgtable(stru
 		return NULL;
 	}
 
+	pt->nents = pages;
 	slen = pci_map_sg(pci,pt->slist,pages,PCI_DMA_FROMDEVICE);
 	if (0 != saa7146_pgtable_build_single(pci, pt, pt->slist, slen)) {
 		return NULL;
@@ -165,6 +166,7 @@ void saa7146_pgtable_free(struct pci_dev
 	if (NULL == pt->cpu)
 		return;
 	pci_free_consistent(pci, pt->size, pt->cpu, pt->dma);
+	pci_unmap_sg(pci, pt->slist, pt->nents, PCI_DMA_FROMDEVICE);
 	pt->cpu = NULL;
 	kfree(pt->slist);
 	pt->slist = NULL;
diff -r a8b2a0738f4e linux/drivers/media/dvb/ttpci/av7110.c
--- a/linux/drivers/media/dvb/ttpci/av7110.c	Thu Apr 19 17:07:37 2007 -0300
+++ b/linux/drivers/media/dvb/ttpci/av7110.c	Sat Apr 28 17:10:38 2007 +0100
@@ -1246,6 +1246,9 @@ static void vpeirq(unsigned long data)
 	if (!budget->feeding1 || (newdma == olddma))
 		return;
 
+	/* Ensure streamed PCI data is synced to CPU */
+	pci_dma_sync_sg_for_cpu(budget->dev->pci, budget->pt.slist, budget->pt.nents, PCI_DMA_FROMDEVICE);
+	
 #if 0 /* keep */
 	/* track rps1 activity */
 	printk("vpeirq: %02x Event Counter 1 0x%04x\n",
diff -r a8b2a0738f4e linux/drivers/media/dvb/ttpci/budget-core.c
--- a/linux/drivers/media/dvb/ttpci/budget-core.c	Thu Apr 19 17:07:37 2007 -0300
+++ b/linux/drivers/media/dvb/ttpci/budget-core.c	Sat Apr 28 17:09:13 2007 +0100
@@ -184,6 +184,9 @@ static void vpeirq(unsigned long data)
 	if (budget->feeding == 0 || newdma == olddma)
 		return;
 
+	/* Ensure streamed PCI data is synced to CPU */
+	pci_dma_sync_sg_for_cpu(budget->dev->pci, budget->pt.slist, budget->pt.nents, PCI_DMA_FROMDEVICE);
+	
 	if (newdma > olddma) {	/* no wraparound, dump olddma..newdma */
 		count = newdma - olddma;
 		dvb_dmx_swfilter_packets(&budget->demux, mem + olddma, count / 188);
diff -r a8b2a0738f4e linux/include/media/saa7146.h
--- a/linux/include/media/saa7146.h	Thu Apr 19 17:07:37 2007 -0300
+++ b/linux/include/media/saa7146.h	Sat Apr 28 17:27:36 2007 +0100
@@ -70,6 +70,7 @@ struct saa7146_pgtable {
 	unsigned long	offset;
 	/* used for custom pagetables (used for example by budget dvb cards) */
 	struct scatterlist *slist;
+	int             nents;
 };
 
 struct saa7146_pci_extension_data {