diff options
| author | Andre Schwarz <andre.schwarz@matrix-vision.de> | 2008-07-10 11:53:16 +0200 |
|---|---|---|
| committer | Grant Likely <grant.likely@secretlab.ca> | 2008-07-12 12:10:12 -0600 |
| commit | 6eb9d32298290b956693fd85c815b817d39a9505 (patch) | |
| tree | 96799533e195fdac4f4e19f5cbdd204bfd9899cf /arch | |
| parent | 0db9360aaa9b95b0cf67f82874809f16e68068eb (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')
| -rw-r--r-- | arch/powerpc/platforms/52xx/mpc52xx_pci.c | 3 |
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 |