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IP22: Disable EARLY PRINTK, because it breaks serial console

PATCH In review Thomas Bogendoerfer 4 participants 6 messages Sep 11, 2007 – Nov 8, 2007 MIPS

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Thomas Bogendoerfer

author maintainer
#0 lore raw

PATCH 1/1 IP22: Disable EARLY PRINTK, because it breaks serial console

Disable EARLY PRINTK, because it breaks serial console

---
 arch/mips/Kconfig |    1 -
 1 files changed, 0 insertions(+), 1 deletions(-)
arch/mips/Kconfig +0 -1
index 3b807b4..1f0502d 100644
@@ -334,7 +334,6 @@ config SGI_IP22
 	select SWAP_IO_SPACE
 	select SYS_HAS_CPU_R4X00
 	select SYS_HAS_CPU_R5000
-	select SYS_HAS_EARLY_PRINTK
 	select SYS_SUPPORTS_32BIT_KERNEL
 	select SYS_SUPPORTS_64BIT_KERNEL
 	select SYS_SUPPORTS_BIG_ENDIAN
Signature · 5 lines
1.4.4.4

-- 
Crap can work. Given enough thrust pigs will fly, but it's not necessary a
good idea.                                                [ RFC1925, 2.3 ]
Tested-by on v1 1/1
#1 lore raw
Quoted 1 line · Thomas Bogendoerfer

Disable EARLY PRINTK, because it breaks serial console

Ralf, at the moment IP22 output stops after "Serial: IP22 Zilog driver (1 chips).". Can you put this patch in until there's a real fix?

Quoted 23 lines
---
 arch/mips/Kconfig |    1 -
 1 files changed, 0 insertions(+), 1 deletions(-)
arch/mips/Kconfig +0 -1
index 3b807b4..1f0502d 100644
@@ -334,7 +334,6 @@ config SGI_IP22
 	select SWAP_IO_SPACE
 	select SYS_HAS_CPU_R4X00
 	select SYS_HAS_CPU_R5000
-	select SYS_HAS_EARLY_PRINTK
 	select SYS_SUPPORTS_32BIT_KERNEL
 	select SYS_SUPPORTS_64BIT_KERNEL
 	select SYS_SUPPORTS_BIG_ENDIAN
Signature · 5 lines
1.4.4.4

-- 
Crap can work. Given enough thrust pigs will fly, but it's not necessary a
good idea.                                                [ RFC1925, 2.3 ]
Signature · 2 lines
Martin Michlmayr
http://www.cyrius.com/
#2 lore raw
Quoted 5 lines · Martin Michlmayr
Quoted 1 line · Thomas Bogendoerfer

Disable EARLY PRINTK, because it breaks serial console

Ralf, at the moment IP22 output stops after "Serial: IP22 Zilog driver (1 chips).". Can you put this patch in until there's a real fix?

Is it by any chance the same problem that I noticed with the DECstation
and reported in the thread starting at:
"http://marc.info/?l=linux-kernel&m=119030963931879&w=2"? If so, there is a fix for the DECstation provided somewhere down the discussion which you may consider porting to IP22. I think the change to the serial core by RMK mentioned there has already been applied upstream.

Ideally, of course, all the SCC drivers should get merged eventually, but
due to subtle (and sometimes broken, as it is the case with the DECstation) differences in wiring for various systems it may never really happen, sigh...

Maciej

author maintainer
#3 lore raw
Quoted 10 lines · Maciej W. Rozycki
Quoted 5 lines · Martin Michlmayr
Quoted 1 line · Thomas Bogendoerfer

Disable EARLY PRINTK, because it breaks serial console

Ralf, at the moment IP22 output stops after "Serial: IP22 Zilog driver (1 chips).". Can you put this patch in until there's a real fix?

Is it by any chance the same problem that I noticed with the DECstation
and reported in the thread starting at:

it's the same problem

Quoted 4 lines

"http://marc.info/?l=linux-kernel&m=119030963931879&w=2"? If so, there is a fix for the DECstation provided somewhere down the discussion which you may consider porting to IP22. I think the change to the serial core by RMK mentioned there has already been applied upstream.

I ported your fix, but it didn't work for me. Maybe because the IP22 zilog driver is still a little bit different than the DEC one.

Quoted 4 lines

Ideally, of course, all the SCC drivers should get merged eventually, but
due to subtle (and sometimes broken, as it is the case with the DECstation) differences in wiring for various systems it may never really happen, sigh...

having a more generic zilog driver with platform backends is quite high on my todo list. But I won't make promisses when this happens...

Thomas.

Signature · 2 lines
Crap can work. Given enough thrust pigs will fly, but it's not necessary a
good idea.                                                [ RFC1925, 2.3 ]
#4 lore raw
Quoted 7 lines · Thomas Bogendoerfer
Quoted 4 lines

Ideally, of course, all the SCC drivers should get merged eventually, but
due to subtle (and sometimes broken, as it is the case with the DECstation) differences in wiring for various systems it may never really happen, sigh...

having a more generic zilog driver with platform backends is quite high on my todo list. But I won't make promisses when this happens...

Right now there are alot of artificial differences between the sun and IP22 8530 drivers by just different prefixes. A good start would already be to unify all these needless differences which is largely a mechanical job. Once that is that is it will become easier to spot all the relevant functional differences - there aren't that many but by now they're well hidden.

Ralf

#5 lore raw
In reply to Thomas Bogendoerfer
Quoted 2 lines · Thomas Bogendoerfer

having a more generic zilog driver with platform backends is quite high on my todo list. But I won't make promisses when this happens...

Synchronous and DMA operation is the tough part, at least for the
DECstation. OTOH, such a framework actually exists already as drivers/net/wan/z85230.[ch], but fitting it into the serial subsystem is a lot of work as the serial core currently has no notion of synchronous modes at all. Ultimately you'd like to be able to switch between asynchronous and synchronous line disciplines on a port by port basis (possibly including halves of the same chip).

Maciej