This patch enables the hardware-fix for the PCI/DMA errata's 19+22 by
setting the FIXD bit in the SDR0_MFR register. Here a description of the
symptoms:
Problem Description
------------------------------
If a DMA is performed between memory and PCI with the DMA 1 Controller
using prefetch, and as a result uses a special purpose buffer selected by
the PCIXn Bridge Options 1 Register (PCIXn_BRDGOPT1[RBP7] - bits 31-29),
the first part of the transfer sequence is performed twice. The
PPC440SPe PCI Controller requests more data than was needed such that in
the case of enforce memory protection, a host CPU exception can occur.
No data is corrupted, because data transfer is stopped in the PCI
Controller. Prefetch enable is specified by setting DMA Configuration
Register (I2O0_DMAx_CFG[DXEPD] - bit 31) to 0.
Behavior that may be observed in a running system
---------------------------------------------------------------------------
1. DMA performance is decreased because of the double access on the PCI bus
interface.
2. If an illegal access to some address on the PCI bus is detected at the
system level, a machine check or similar system error may occur.
Workarounds Available
----------------------------------
1. Do not program prefetch. Note that a prefetch command cannot be programmed
without selecting a special purpose buffer.
2. To avoid crossing a physical boundary of the PCI slave device, add 512
bytes of address to the PCI address range.
This patch was originally provided by Pravin M. Bathija <pbathija@amcc.com>
from AMCC and slighly changed.
Signed-off-by: Pravin M. Bathija <pbathija@amcc.com>
Signed-off-by: Stefan Roese <sr@denx.de>
This patch removes the CFG_PCI_PRE_INIT option completely, since
it's not needed anymore with the patch from Matthias Fuchs with
the "weak" pci_pre_init() implementation.
Signed-off-by: Stefan Roese <sr@denx.de>
The AMCC Luan now uses the common 440SP(e) DDR SPD code for DDR
inititializition. This includes DDR auto calibration and support
for different DIMM modules, instead of the fixed setup used in
the earlier version.
This patch also enables the cache in FLASH for the startup
phase of U-Boot (while running from FLASH). After relocating to
SDRAM the cache is disabled again. This will speed up the boot
process, especially the SDRAM setup, since there are some loops
for memory testing (auto calibration).
Signed-off-by: Stefan Roese <sr@denx.de>
Stefan Roese
Grzegorz Bernacki
Wolfgang Denk