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authorAndre Schwarz <andre.schwarz@matrix-vision.de>2008-07-10 11:53:16 +0200
committerGrant Likely <grant.likely@secretlab.ca>2008-07-12 12:10:12 -0600
commit6eb9d32298290b956693fd85c815b817d39a9505 (patch)
tree96799533e195fdac4f4e19f5cbdd204bfd9899cf /arch/powerpc/platforms
parent0db9360aaa9b95b0cf67f82874809f16e68068eb (diff)
powerpc/mpc5200: PCI write combine timer
On MPC5200 the PCI target control register (PCITCR) @ MBAR + 0xD6C is initialized with only bit 7 (Latrule disable) set. The 8-Bit write combine timer (Bits 24..31) should be also set to a reasonable value _greater zero_ (0x08 = default) since setting it to 0x00 leads to _very poor_ performance as a PCI target since external burst won't be possible at all. Setting the WCT to 0x08 (cache-line size) leads to good overall perfomance. Signed-off-by: Andre Schwarz <andre.schwarz@matrix-vision.de> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Diffstat (limited to 'arch/powerpc/platforms')
-rw-r--r--arch/powerpc/platforms/52xx/mpc52xx_pci.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/powerpc/platforms/52xx/mpc52xx_pci.c b/arch/powerpc/platforms/52xx/mpc52xx_pci.c
index e3428ddd904..5a382bb15f6 100644
--- a/arch/powerpc/platforms/52xx/mpc52xx_pci.c
+++ b/arch/powerpc/platforms/52xx/mpc52xx_pci.c
@@ -63,6 +63,7 @@
#define MPC52xx_PCI_TCR_P 0x01000000
#define MPC52xx_PCI_TCR_LD 0x00010000
+#define MPC52xx_PCI_TCR_WCT8 0x00000008
#define MPC52xx_PCI_TBATR_DISABLE 0x0
#define MPC52xx_PCI_TBATR_ENABLE 0x1
@@ -313,7 +314,7 @@ mpc52xx_pci_setup(struct pci_controller *hose,
out_be32(&pci_regs->tbatr1,
MPC52xx_PCI_TBATR_ENABLE | MPC52xx_PCI_TARGET_MEM );
- out_be32(&pci_regs->tcr, MPC52xx_PCI_TCR_LD);
+ out_be32(&pci_regs->tcr, MPC52xx_PCI_TCR_LD | MPC52xx_PCI_TCR_WCT8);
tmp = in_be32(&pci_regs->gscr);
#if 0