Fix IDE CD-drive PIO mode.

CD drives in PIO mode don't work under Xen because of a change in Linux
between 2.6.12 and 2.6.16, as a result of the following thread:
http://lists.parisc-linux.org/pipermail/parisc-linux/2005-August/027197.html

The change breaks systems which have highmem and a swiotlb because the
ide-cd driver doesn't use the swiotlb, resulting in read/writes to/from
highmem pages in PIO mode not working any longer.  Xen kernels usually have
both highmem and a swiotlb.

Signed-off-by: Christian Limpach <Christian.Limpach@cl.cam.ac.uk>
xen-unstable changeset: 10151:ad33b3882867f6ab4466383129aa3827c64508d3
xen-unstable date: Wed May 24 19:41:47 2006 +0100

diff --git a/patches/linux-2.6.16.13/fix-ide-cd-pio-mode.patch b/patches/linux-2.6.16.13/fix-ide-cd-pio-mode.patch
new file mode 100644 (file)
index 0000000..0892117
--- /dev/null
+++ b/patches/linux-2.6.16.13/fix-ide-cd-pio-mode.patch
@@ -0,0 +1,18 @@
+diff -ru ../pristine-linux-2.6.16.13/drivers/ide/ide-lib.c ./drivers/ide/ide-lib.c
+--- ../pristine-linux-2.6.16.13/drivers/ide/ide-lib.c  2006-05-02 22:38:44.000000000 +0100
++++ ./drivers/ide/ide-lib.c    2006-05-24 18:37:05.000000000 +0100
+@@ -410,10 +410,10 @@
+ {
+       u64 addr = BLK_BOUNCE_HIGH;     /* dma64_addr_t */
+ 
+-      if (!PCI_DMA_BUS_IS_PHYS) {
+-              addr = BLK_BOUNCE_ANY;
+-      } else if (on && drive->media == ide_disk) {
+-              if (HWIF(drive)->pci_dev)
++      if (on && drive->media == ide_disk) {
++              if (!PCI_DMA_BUS_IS_PHYS)
++                      addr = BLK_BOUNCE_ANY;
++              else if (HWIF(drive)->pci_dev)
+                       addr = HWIF(drive)->pci_dev->dma_mask;
+       }
+