Re: [RESEND PATCH] arm: assabet_defconfig: disable IDE subsystem

[Russell King - ARM Linux]

On Thu, Mar 09, 2017 at 03:24:56PM +0300, Sergei Shtylyov wrote:
> On 03/09/2017 03:20 PM, Sekhar Nori wrote:
> 
> >[...]
> 
> >>>diff --git a/arch/arm/mach-davinci/board-dm644x-evm.c
> >>>b/arch/arm/mach-davinci/board-dm644x-evm.c
> >>>index 023480b75244..60a1f23890cd 100644
> >>>--- a/arch/arm/mach-davinci/board-dm644x-evm.c
> >>>+++ b/arch/arm/mach-davinci/board-dm644x-evm.c
> >>>@@ -744,7 +744,7 @@ static int davinci_phy_fixup(struct phy_device
> >>>*phydev)
> >>>     return 0;
> >>> }
> >>>
> >>>-#define HAS_ATA        IS_ENABLED(CONFIG_BLK_DEV_PALMCHIP_BK3710)
> >>>+#define HAS_ATA        IS_ENABLED(CONFIG_PATA_BK3710)
> >>
> >>   I think it would be more correct to check for both libata and IDE
> >>drivers here...
> >
> >As I understand, the plan is to remove the IDE driver soon.
> 
>    I'm not sure DaveM would support any removals in drivers/ide/. He has
> explicitly expressed his will to maintain the IDE driuver forever.

As I keep saying, there are ARM machines where the IDE driver works but
the PATA driver doesn't.  EBSA110's PCMCIA slots for instance.

Yes, it's very obscure - but what it comes down to is the silly way the
"ISA" IO is handled on the platform (which depends whether it's an 8-bit
or 16-bit ISA-style peripheral.)  The old IDE CS driver _could_ be bent
to work via a patch like this:

ARM: EBSA110: Enable 16-bit IO type for ide-iops

diff --git a/arch/arm/Makefile b/arch/arm/Makefile
index 047a20780fc1..2eb501d6b5fe 100644
--- a/arch/arm/Makefile
+++ b/arch/arm/Makefile
@@ -217,7 +217,8 @@ ifeq ($(CONFIG_ARCH_EBSA110),y)
 # This is what happens if you forget the IOCS16 line.
 # PCMCIA cards stop working.
 CFLAGS_3c589_cs.o :=-DISA_SIXTEEN_BIT_PERIPHERAL
-export CFLAGS_3c589_cs.o
+CFLAGS_ide-io-std.o :=-DISA_SIXTEEN_BIT_PERIPHERAL
+export CFLAGS_3c589_cs.o CFLAGS_ide-io-std.o
 endif

 # The byte offset of the kernel image in RAM from the start of RAM.

but the PATA driver is much harder.

That said, the EBSA110 is now a prime museum piece, and towards the
end of the time I was using it, the kernel was becoming more and more
inefficient on the hardware - as in, it appeared it could route
network packets _or_ run userspace, but not both, even with drivers
converted to NAPI.

-- 
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