Re: [PATCH 3/9] PCI: Disable cardbus bridge MEM1 pref CTL

From: Jesse Barnes
Date: Fri Feb 10 2012 - 15:46:16 EST


On Sat, 4 Feb 2012 22:55:02 -0800
Yinghai Lu <yinghai@xxxxxxxxxx> wrote:

> Some BIOS enable both pref for MEM0 and MEM1.
>
> but we assume MEM1 is non-pref...
>
> Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx>
> ---
> drivers/pci/setup-bus.c | 8 ++++++++
> 1 files changed, 8 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
> index 090217a..d5897c3 100644
> --- a/drivers/pci/setup-bus.c
> +++ b/drivers/pci/setup-bus.c
> @@ -914,6 +914,14 @@ static void pci_bus_size_cardbus(struct pci_bus *bus,
> if (realloc_head)
> add_to_list(realloc_head, bridge, b_res+1, pci_cardbus_io_size, 0 /* dont care */);
>
> + /* MEM1 must not be pref mmio */
> + pci_read_config_word(bridge, PCI_CB_BRIDGE_CONTROL, &ctrl);
> + if (ctrl & PCI_CB_BRIDGE_CTL_PREFETCH_MEM1) {
> + ctrl &= ~PCI_CB_BRIDGE_CTL_PREFETCH_MEM1;
> + pci_write_config_word(bridge, PCI_CB_BRIDGE_CONTROL, ctrl);
> + pci_read_config_word(bridge, PCI_CB_BRIDGE_CONTROL, &ctrl);
> + }
> +
> /*
> * Check whether prefetchable memory is supported
> * by this bridge.

Does this actually fix any bugs? Dominik, have you tested it?

Thanks,
--
Jesse Barnes, Intel Open Source Technology Center

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