[PATCH 0/2] MIPS: Malta: Fix PCI southbridge legacy resource clashes

[PATCH 0/2] MIPS: Malta: Fix PCI southbridge legacy resource clashes

[Maciej W. Rozycki]

Hi,

 This mini patch series sorts out issues with southbridge legacy resource 
management on the MIPS Malta platform.  Two changes turned out required, 
because merely removing the clash would regress the PS/2 interfaces, fixed 
by accident with the PCIBIOS_MIN_IO fix.

 This does prove nobody has used these interfaces since forever, or most 
likely since the move to the new serio driver.  Things most likely worked 
fine with 2.4 and I still have such old Malta kernel builds lying around 
(though sadly no hardware to try with), although I do know I've never used 
the PS/2 stuff with this platform, e.g. quoting an arbitrarily picked 
2.4.19-rc1 bootstrap log:

CPU revision is: 00018101
Primary instruction cache 16kb, linesize 32 bytes(4 ways)
Primary data cache 16kb, linesize 32 bytes (4 ways)
Linux version 2.4.19-rc1 (macro@macro.ds2.pg.gda.pl) (gcc version 2.95.4 20010319 (prerelease)) #1 Fri Aug 23 02:55:02 CEST 2002
[...]
parport0: PC-style at 0x378 [PCSPP,EPP]
initialize_kbd: Keyboard reset failed, no ACK
Detected PS/2 Mouse Port.
pty: 256 Unix98 ptys configured
keyboard: Timeout - AT keyboard not present?(ed)
keyboard: Timeout - AT keyboard not present?(f4)
Serial driver version 5.05c (2001-07-08) with MANY_PORTS SHARE_IRQ DETECT_IRQ SERIAL_PCI enabled
[...]

However to prevent the PS/2 interfaces from getting fixed and then broken 
again with backports in a random fashion I have marked both changes for 
backporting as appropriate.

 Bjorn, may I request that these changes be placed, with Thomas's ack of 
course (hopefully a formality), ahead of Ilpo's commit 16fbaba2b78f 
("MIPS: Malta: Use pcibios_align_resource() to block io range") (or 
whatever the latest version is, as said commit seems to be missing tags 
updates you mentioned), and then merged via your tree?  That will prevent 
things from breaking just to be fixed again shortly, and overall getting 
out of sync.

 See individual commit descriptions for details.

  Maciej

[PATCH 1/2] MIPS: Malta: Fix keyboard resource preventing i8042 driver from registering

[Maciej W. Rozycki]

MIPS Malta platform code registers the PCI southbridge legacy port I/O 
PS/2 keyboard range as a standard resource marked as busy.  It prevents 
the i8042 driver from registering as it fails to claim the resource in 
a call to i8042_platform_init().  Consequently PS/2 keyboard and mouse 
devices cannot be used with this platform.

Fix the issue by removing the busy marker from the standard reservation, 
making the driver register successfully:

serio: i8042 KBD port at 0x60,0x64 irq 1
serio: i8042 AUX port at 0x60,0x64 irq 12

and the resource show up as expected among the legacy devices:

00000000-00ffffff : MSC PCI I/O
  00000000-0000001f : dma1
  00000020-00000021 : pic1
  00000040-0000005f : timer
  00000060-0000006f : keyboard
    00000060-0000006f : i8042
  00000070-00000077 : rtc0
  00000080-0000008f : dma page reg
  000000a0-000000a1 : pic2
  000000c0-000000df : dma2
  [...]

If the i8042 driver has not been configured, then the standard resource 
will remain there preventing any conflicting dynamic assignment of this 
PCI port I/O address range.

Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Cc: stable@vger.kernel.org
---
 arch/mips/mti-malta/malta-setup.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

linux-mips-malta-setup-resource-keyboard.diff
Index: linux-macro/arch/mips/mti-malta/malta-setup.c
===================================================================
--- linux-macro.orig/arch/mips/mti-malta/malta-setup.c
+++ linux-macro/arch/mips/mti-malta/malta-setup.c
@@ -47,7 +47,7 @@ static struct resource standard_io_resou
 		.name = "keyboard",
 		.start = 0x60,
 		.end = 0x6f,
-		.flags = IORESOURCE_IO | IORESOURCE_BUSY
+		.flags = IORESOURCE_IO
 	},
 	{
 		.name = "dma page reg",

[PATCH 2/2] MIPS: Malta: Fix PCI southbridge legacy resource reservations

[Maciej W. Rozycki]

Covering the PCI southbridge legacy port I/O range with a northbridge 
resource reservation prevents MIPS Malta platform code from claiming its 
standard legacy resources.  This is because request_resource() calls 
cause a clash with the previous reservation and consequently fail.

Change to using insert_resource() so as to prevent the clash, switching 
the legacy reservations from:

00000000-00ffffff : MSC PCI I/O
  00000020-00000021 : pic1
  00000070-00000077 : rtc0
  000000a0-000000a1 : pic2
  [...]

to:

00000000-00ffffff : MSC PCI I/O
  00000000-0000001f : dma1
  00000020-00000021 : pic1
  00000040-0000005f : timer
  00000060-0000006f : keyboard
  00000070-00000077 : rtc0
  00000080-0000008f : dma page reg
  000000a0-000000a1 : pic2
  000000c0-000000df : dma2
  [...]

Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Fixes: ae81aad5c2e1 ("MIPS: PCI: Use pci_enable_resources()")
Cc: stable@vger.kernel.org # v6.18+
---
 arch/mips/mti-malta/malta-setup.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

linux-mips-malta-setup-insert-resource.diff
Index: linux-macro/arch/mips/mti-malta/malta-setup.c
===================================================================
--- linux-macro.orig/arch/mips/mti-malta/malta-setup.c
+++ linux-macro/arch/mips/mti-malta/malta-setup.c
@@ -213,7 +213,7 @@ void __init plat_mem_setup(void)
 
 	/* Request I/O space for devices used on the Malta board. */
 	for (i = 0; i < ARRAY_SIZE(standard_io_resources); i++)
-		request_resource(&ioport_resource, standard_io_resources+i);
+		insert_resource(&ioport_resource, standard_io_resources + i);
 
 	/*
 	 * Enable DMA channel 4 (cascade channel) in the PIIX4 south bridge.

Re: [PATCH 1/2] MIPS: Malta: Fix keyboard resource preventing i8042 driver from registering

[Thomas Bogendoerfer]

On Tue, Oct 21, 2025 at 08:38:22PM +0100, Maciej W. Rozycki wrote:
> MIPS Malta platform code registers the PCI southbridge legacy port I/O 
> PS/2 keyboard range as a standard resource marked as busy.  It prevents 
> the i8042 driver from registering as it fails to claim the resource in 
> a call to i8042_platform_init().  Consequently PS/2 keyboard and mouse 
> devices cannot be used with this platform.
> 
> Fix the issue by removing the busy marker from the standard reservation, 
> making the driver register successfully:
> 
> serio: i8042 KBD port at 0x60,0x64 irq 1
> serio: i8042 AUX port at 0x60,0x64 irq 12
> 
> and the resource show up as expected among the legacy devices:
> 
> 00000000-00ffffff : MSC PCI I/O
>   00000000-0000001f : dma1
>   00000020-00000021 : pic1
>   00000040-0000005f : timer
>   00000060-0000006f : keyboard
>     00000060-0000006f : i8042
>   00000070-00000077 : rtc0
>   00000080-0000008f : dma page reg
>   000000a0-000000a1 : pic2
>   000000c0-000000df : dma2
>   [...]
> 
> If the i8042 driver has not been configured, then the standard resource 
> will remain there preventing any conflicting dynamic assignment of this 
> PCI port I/O address range.
> 
> Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
> Cc: stable@vger.kernel.org
> ---
>  arch/mips/mti-malta/malta-setup.c |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> linux-mips-malta-setup-resource-keyboard.diff
> Index: linux-macro/arch/mips/mti-malta/malta-setup.c
> ===================================================================
> --- linux-macro.orig/arch/mips/mti-malta/malta-setup.c
> +++ linux-macro/arch/mips/mti-malta/malta-setup.c
> @@ -47,7 +47,7 @@ static struct resource standard_io_resou
>  		.name = "keyboard",
>  		.start = 0x60,
>  		.end = 0x6f,
> -		.flags = IORESOURCE_IO | IORESOURCE_BUSY
> +		.flags = IORESOURCE_IO
>  	},
>  	{
>  		.name = "dma page reg",

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

-- 
Crap can work. Given enough thrust pigs will fly, but it's not necessarily a
good idea.                                                [ RFC1925, 2.3 ]

Re: [PATCH 2/2] MIPS: Malta: Fix PCI southbridge legacy resource reservations

[Thomas Bogendoerfer]

On Tue, Oct 21, 2025 at 08:38:29PM +0100, Maciej W. Rozycki wrote:
> Covering the PCI southbridge legacy port I/O range with a northbridge 
> resource reservation prevents MIPS Malta platform code from claiming its 
> standard legacy resources.  This is because request_resource() calls 
> cause a clash with the previous reservation and consequently fail.
> 
> Change to using insert_resource() so as to prevent the clash, switching 
> the legacy reservations from:
> 
> 00000000-00ffffff : MSC PCI I/O
>   00000020-00000021 : pic1
>   00000070-00000077 : rtc0
>   000000a0-000000a1 : pic2
>   [...]
> 
> to:
> 
> 00000000-00ffffff : MSC PCI I/O
>   00000000-0000001f : dma1
>   00000020-00000021 : pic1
>   00000040-0000005f : timer
>   00000060-0000006f : keyboard
>   00000070-00000077 : rtc0
>   00000080-0000008f : dma page reg
>   000000a0-000000a1 : pic2
>   000000c0-000000df : dma2
>   [...]
> 
> Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
> Fixes: ae81aad5c2e1 ("MIPS: PCI: Use pci_enable_resources()")
> Cc: stable@vger.kernel.org # v6.18+
> ---
>  arch/mips/mti-malta/malta-setup.c |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> linux-mips-malta-setup-insert-resource.diff
> Index: linux-macro/arch/mips/mti-malta/malta-setup.c
> ===================================================================
> --- linux-macro.orig/arch/mips/mti-malta/malta-setup.c
> +++ linux-macro/arch/mips/mti-malta/malta-setup.c
> @@ -213,7 +213,7 @@ void __init plat_mem_setup(void)
>  
>  	/* Request I/O space for devices used on the Malta board. */
>  	for (i = 0; i < ARRAY_SIZE(standard_io_resources); i++)
> -		request_resource(&ioport_resource, standard_io_resources+i);
> +		insert_resource(&ioport_resource, standard_io_resources + i);
>  
>  	/*
>  	 * Enable DMA channel 4 (cascade channel) in the PIIX4 south bridge.

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

-- 
Crap can work. Given enough thrust pigs will fly, but it's not necessarily a
good idea.                                                [ RFC1925, 2.3 ]

Re: [PATCH 0/2] MIPS: Malta: Fix PCI southbridge legacy resource clashes

[Bjorn Helgaas]

[+cc linux-pci]

On Tue, Oct 21, 2025 at 08:38:15PM +0100, Maciej W. Rozycki wrote:
> Hi,
> 
>  This mini patch series sorts out issues with southbridge legacy resource 
> management on the MIPS Malta platform.  Two changes turned out required, 
> because merely removing the clash would regress the PS/2 interfaces, fixed 
> by accident with the PCIBIOS_MIN_IO fix.
> 
>  This does prove nobody has used these interfaces since forever, or most 
> likely since the move to the new serio driver.  Things most likely worked 
> fine with 2.4 and I still have such old Malta kernel builds lying around 
> (though sadly no hardware to try with), although I do know I've never used 
> the PS/2 stuff with this platform, e.g. quoting an arbitrarily picked 
> 2.4.19-rc1 bootstrap log:
> 
> CPU revision is: 00018101
> Primary instruction cache 16kb, linesize 32 bytes(4 ways)
> Primary data cache 16kb, linesize 32 bytes (4 ways)
> Linux version 2.4.19-rc1 (macro@macro.ds2.pg.gda.pl) (gcc version 2.95.4 20010319 (prerelease)) #1 Fri Aug 23 02:55:02 CEST 2002
> [...]
> parport0: PC-style at 0x378 [PCSPP,EPP]
> initialize_kbd: Keyboard reset failed, no ACK
> Detected PS/2 Mouse Port.
> pty: 256 Unix98 ptys configured
> keyboard: Timeout - AT keyboard not present?(ed)
> keyboard: Timeout - AT keyboard not present?(f4)
> Serial driver version 5.05c (2001-07-08) with MANY_PORTS SHARE_IRQ DETECT_IRQ SERIAL_PCI enabled
> [...]
> 
> However to prevent the PS/2 interfaces from getting fixed and then broken 
> again with backports in a random fashion I have marked both changes for 
> backporting as appropriate.
> 
>  Bjorn, may I request that these changes be placed, with Thomas's ack of 
> course (hopefully a formality), ahead of Ilpo's commit 16fbaba2b78f 
> ("MIPS: Malta: Use pcibios_align_resource() to block io range") (or 
> whatever the latest version is, as said commit seems to be missing tags 
> updates you mentioned), and then merged via your tree?  That will prevent 
> things from breaking just to be fixed again shortly, and overall getting 
> out of sync.
> 
>  See individual commit descriptions for details.
> 
>   Maciej

Applied with Thomas's acks to pci/for-linus for v6.18, thanks!

Re: [PATCH 0/2] MIPS: Malta: Fix PCI southbridge legacy resource clashes

[Ilpo Järvinen]

[-- Attachment #1: Type: text/plain, Size: 2213 bytes --]

On Tue, 21 Oct 2025, Maciej W. Rozycki wrote:

> Hi,
> 
>  This mini patch series sorts out issues with southbridge legacy resource 
> management on the MIPS Malta platform.  Two changes turned out required, 
> because merely removing the clash would regress the PS/2 interfaces, fixed 
> by accident with the PCIBIOS_MIN_IO fix.
> 
>  This does prove nobody has used these interfaces since forever, or most 
> likely since the move to the new serio driver.  Things most likely worked 
> fine with 2.4 and I still have such old Malta kernel builds lying around 
> (though sadly no hardware to try with), although I do know I've never used 
> the PS/2 stuff with this platform, e.g. quoting an arbitrarily picked 
> 2.4.19-rc1 bootstrap log:
> 
> CPU revision is: 00018101
> Primary instruction cache 16kb, linesize 32 bytes(4 ways)
> Primary data cache 16kb, linesize 32 bytes (4 ways)
> Linux version 2.4.19-rc1 (macro@macro.ds2.pg.gda.pl) (gcc version 2.95.4 20010319 (prerelease)) #1 Fri Aug 23 02:55:02 CEST 2002
> [...]
> parport0: PC-style at 0x378 [PCSPP,EPP]
> initialize_kbd: Keyboard reset failed, no ACK
> Detected PS/2 Mouse Port.
> pty: 256 Unix98 ptys configured
> keyboard: Timeout - AT keyboard not present?(ed)
> keyboard: Timeout - AT keyboard not present?(f4)
> Serial driver version 5.05c (2001-07-08) with MANY_PORTS SHARE_IRQ DETECT_IRQ SERIAL_PCI enabled
> [...]
> 
> However to prevent the PS/2 interfaces from getting fixed and then broken 
> again with backports in a random fashion I have marked both changes for 
> backporting as appropriate.
> 
>  Bjorn, may I request that these changes be placed, with Thomas's ack of 
> course (hopefully a formality), ahead of Ilpo's commit 16fbaba2b78f 
> ("MIPS: Malta: Use pcibios_align_resource() to block io range") (or 
> whatever the latest version is, as said commit seems to be missing tags 
> updates you mentioned), and then merged via your tree?  That will prevent 
> things from breaking just to be fixed again shortly, and overall getting 
> out of sync.
> 
>  See individual commit descriptions for details.

FWIW,

Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

-- 
 i.

Re: [PATCH 2/2] MIPS: Malta: Fix PCI southbridge legacy resource reservations

[Jonas Gorski]

Hi,

On Tue, Oct 21, 2025 at 9:38 PM Maciej W. Rozycki <macro@orcam.me.uk> wrote:
>
> Covering the PCI southbridge legacy port I/O range with a northbridge
> resource reservation prevents MIPS Malta platform code from claiming its
> standard legacy resources.  This is because request_resource() calls
> cause a clash with the previous reservation and consequently fail.
>
> Change to using insert_resource() so as to prevent the clash, switching
> the legacy reservations from:
>
> 00000000-00ffffff : MSC PCI I/O
>   00000020-00000021 : pic1
>   00000070-00000077 : rtc0
>   000000a0-000000a1 : pic2
>   [...]
>
> to:
>
> 00000000-00ffffff : MSC PCI I/O
>   00000000-0000001f : dma1
>   00000020-00000021 : pic1
>   00000040-0000005f : timer
>   00000060-0000006f : keyboard
>   00000070-00000077 : rtc0
>   00000080-0000008f : dma page reg
>   000000a0-000000a1 : pic2
>   000000c0-000000df : dma2
>   [...]
>
> Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
> Fixes: ae81aad5c2e1 ("MIPS: PCI: Use pci_enable_resources()")
> Cc: stable@vger.kernel.org # v6.18+
> ---
>  arch/mips/mti-malta/malta-setup.c |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> linux-mips-malta-setup-insert-resource.diff
> Index: linux-macro/arch/mips/mti-malta/malta-setup.c
> ===================================================================
> --- linux-macro.orig/arch/mips/mti-malta/malta-setup.c
> +++ linux-macro/arch/mips/mti-malta/malta-setup.c
> @@ -213,7 +213,7 @@ void __init plat_mem_setup(void)
>
>         /* Request I/O space for devices used on the Malta board. */

This comment doesn't match the code anymore.

>         for (i = 0; i < ARRAY_SIZE(standard_io_resources); i++)
> -               request_resource(&ioport_resource, standard_io_resources+i);
> +               insert_resource(&ioport_resource, standard_io_resources + i);
>
>         /*
>          * Enable DMA channel 4 (cascade channel) in the PIIX4 south bridge.
>

Best regards,
Jonas

Re: [PATCH 2/2] MIPS: Malta: Fix PCI southbridge legacy resource reservations

[Maciej W. Rozycki]

On Wed, 22 Oct 2025, Jonas Gorski wrote:

> > Index: linux-macro/arch/mips/mti-malta/malta-setup.c
> > ===================================================================
> > --- linux-macro.orig/arch/mips/mti-malta/malta-setup.c
> > +++ linux-macro/arch/mips/mti-malta/malta-setup.c
> > @@ -213,7 +213,7 @@ void __init plat_mem_setup(void)
> >
> >         /* Request I/O space for devices used on the Malta board. */
> 
> This comment doesn't match the code anymore.

 Thank you for your input.  How do you propose to reword the comment then?  
The resources are still claimed, it's only the way that has changed.  Is 
s/Request/Claim/ what you're after?

  Maciej