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Date:   Thu, 2 Sep 2021 13:08:04 +0200
From:   Thomas Bogendoerfer <tsbogend@alpha.franken.de>
To:     Sergio Paracuellos <sergio.paracuellos@gmail.com>
Cc:     bhelgaas@google.com, matthias.bgg@gmail.com,
        gregkh@linuxfoundation.org, linux-mips@vger.kernel.org,
        linux-pci@vger.kernel.org, linux-staging@lists.linux.dev,
        neil@brown.name, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 1/3] MIPS: ralink: don't define PC_IOBASE but increase
 IO_SPACE_LIMIT
Message-ID: <20210902110804.GA7614@alpha.franken.de>
References: <20210822161005.22467-1-sergio.paracuellos@gmail.com>
 <20210822161005.22467-2-sergio.paracuellos@gmail.com>
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On Sun, Aug 22, 2021 at 06:10:03PM +0200, Sergio Paracuellos wrote:
> Defining PCI_IOBASE results in pci resource handling working but the
> addresses generated for IO accesses are wrong since the ioremap in the pci core
> function 'pci_parse_request_of_pci_ranges' tries to remap to a fixed virtual
> address (PC_IOBASE) which can't work for KSEG1 addresses. To get it working this
> way, we would need to put PCI_IOBASE somewhere into KSEG2 which will result in
> creating TLB entries for IO addresses, which most of the time isn't needed on
> MIPS because of access via KSEG1. So avoid to define PCI_IOBASE and increase
> IO_SPACE_LIMIT resource for ralink MIPS platform instead, to get valid IO
> addresses for resources from pci core 'pci_address_to_pio' function.
> 
> Fixes: 222b27713d7f ("MIPS: ralink: Define PCI_IOBASE)
> Signed-off-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>
> ---
>  arch/mips/include/asm/mach-ralink/spaces.h | 4 +---
>  1 file changed, 1 insertion(+), 3 deletions(-)
> 
> diff --git a/arch/mips/include/asm/mach-ralink/spaces.h b/arch/mips/include/asm/mach-ralink/spaces.h
> index 87d085c9ad61..31a3525213cf 100644
> --- a/arch/mips/include/asm/mach-ralink/spaces.h
> +++ b/arch/mips/include/asm/mach-ralink/spaces.h
> @@ -2,9 +2,7 @@
>  #ifndef __ASM_MACH_RALINK_SPACES_H_
>  #define __ASM_MACH_RALINK_SPACES_H_
>  
> -#define PCI_IOBASE	_AC(0xa0000000, UL)
> -#define PCI_IOSIZE	SZ_16M
> -#define IO_SPACE_LIMIT	(PCI_IOSIZE - 1)
> +#define IO_SPACE_LIMIT	0x1fffffff
>  
>  #include <asm/mach-generic/spaces.h>
>  #endif
> -- 
> 2.25.1


Acked-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

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