V4L/DVB (5592): DMA: Correctly free resources on error, sync PCI streamed data

I added saa7146_vmalloc_destroy_pgtable() which frees the resources
allocated by saa7146_vmalloc_build_pgtable() and updated the callers in
budget-core.c and av7110.c. I have also been through the updated
functions and updated the error paths to ensure they free all allocated
resources on error.
I also realised that there are other callers to saa7146_pgtable_free()
which did not have any sg DMA mapped so it seems wrong to add the
pci_unmap_sg() into that function. Instead I created
saa7146_vmalloc_destroy_pgtable() to do this.
Also included in this patch are the previous fixes for pci_unmap_sg()
and syncing the PCI streamed data to work with a SWIOTLB and match the
requirements documented in DMA-API.txt.

Signed-off-by: Jon Burgess <jburgess777@googlemail.com>
Signed-off-by: Oliver Endriss <o.endriss@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

1 files changed, 6 insertions, 3 deletions

diff --git a/drivers/media/dvb/ttpci/av7110.c b/drivers/media/dvb/ttpci/av7110.c
index 67becdd4db6..ef1108c0bf1 100644
--- a/drivers/media/dvb/ttpci/av7110.c
+++ b/drivers/media/dvb/ttpci/av7110.c
@@ -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
         /* track rps1 activity */
         printk("vpeirq: %02x Event Counter 1 0x%04x\n",
@@ -2679,8 +2682,8 @@ err_iobuf_vfree_6:
 err_pci_free_5:
         pci_free_consistent(pdev, 8192, av7110->debi_virt, av7110->debi_bus);
 err_saa71466_vfree_4:
-        if (!av7110->grabbing)
-                saa7146_pgtable_free(pdev, &av7110->pt);
+        if (av7110->grabbing)
+                saa7146_vfree_destroy_pgtable(pdev, av7110->grabbing, &av7110->pt);
 err_i2c_del_3:
         i2c_del_adapter(&av7110->i2c_adap);
 err_dvb_unregister_adapter_2:
@@ -2710,7 +2713,7 @@ static int __devexit av7110_detach(struct saa7146_dev* saa)
                 SAA7146_ISR_CLEAR(saa, MASK_10);
                 msleep(50);
                 tasklet_kill(&av7110->vpe_tasklet);
-                saa7146_pgtable_free(saa->pci, &av7110->pt);
+                saa7146_vfree_destroy_pgtable(saa->pci, av7110->grabbing, &av7110->pt);
         }
         av7110_exit_v4l(av7110);