2020-05-20 05:27:46

by Christian Borntraeger

[permalink] [raw]
Subject: Re: [PATCH] s390/sclp_vt220: Fix console name to match device


On 19.05.20 20:16, Valentin Vidic wrote:
> Console name reported in /proc/consoles:
>
> ttyS1 -W- (EC p ) 4:65
>
> does not match device name:
>
> crw--w---- 1 root root 4, 65 May 17 12:18 /dev/ttysclp0
>
> so debian-installer gets confused and fails to start.
>
> Signed-off-by: Valentin Vidic <[email protected]>
> Cc: [email protected]

This is not as simple. ttyS1 is the the console name and ttysclp0 is the tty name.
This has mostly historic reasons and it obviously causes problems.
But there is documentation out that that actually describes the use of
console=ttyS1 console=ttyS0.
to have console output on both sclp consoles and there are probably scripts
using ttyS1.

I am wondering. The tty for ttyS0 is named sclp_line0. Does this work in LPAR?


> ---
> drivers/s390/char/sclp_vt220.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/s390/char/sclp_vt220.c b/drivers/s390/char/sclp_vt220.c
> index 3f9a6ef650fa..3c2ed6d01387 100644
> --- a/drivers/s390/char/sclp_vt220.c
> +++ b/drivers/s390/char/sclp_vt220.c
> @@ -35,8 +35,8 @@
> #define SCLP_VT220_MINOR 65
> #define SCLP_VT220_DRIVER_NAME "sclp_vt220"
> #define SCLP_VT220_DEVICE_NAME "ttysclp"
> -#define SCLP_VT220_CONSOLE_NAME "ttyS"
> -#define SCLP_VT220_CONSOLE_INDEX 1 /* console=ttyS1 */
> +#define SCLP_VT220_CONSOLE_NAME "ttysclp"
> +#define SCLP_VT220_CONSOLE_INDEX 0 /* console=ttysclp0 */
>
> /* Representation of a single write request */
> struct sclp_vt220_request {
>


2020-05-20 07:09:38

by Valentin Vidić

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Subject: Re: [PATCH] s390/sclp_vt220: Fix console name to match device

On Wed, May 20, 2020 at 07:25:06AM +0200, Christian Borntraeger wrote:
> This is not as simple. ttyS1 is the the console name and ttysclp0 is the tty name.
> This has mostly historic reasons and it obviously causes problems.
> But there is documentation out that that actually describes the use of
> console=ttyS1 console=ttyS0.
> to have console output on both sclp consoles and there are probably scripts
> using ttyS1.
>
> I am wondering. The tty for ttyS0 is named sclp_line0. Does this work in LPAR?

I ran into this problem with qemu-system-s390x, so not sure about LPAR.
Would changing the tty name also cause problems?

--
Valentin

2020-05-20 07:16:58

by Christian Borntraeger

[permalink] [raw]
Subject: Re: [PATCH] s390/sclp_vt220: Fix console name to match device



On 20.05.20 09:07, Valentin Vidić wrote:
> On Wed, May 20, 2020 at 07:25:06AM +0200, Christian Borntraeger wrote:
>> This is not as simple. ttyS1 is the the console name and ttysclp0 is the tty name.
>> This has mostly historic reasons and it obviously causes problems.
>> But there is documentation out that that actually describes the use of
>> console=ttyS1 console=ttyS0.
>> to have console output on both sclp consoles and there are probably scripts
>> using ttyS1.
>>
>> I am wondering. The tty for ttyS0 is named sclp_line0. Does this work in LPAR?
>
> I ran into this problem with qemu-system-s390x, so not sure about LPAR.
> Would changing the tty name also cause problems?

My point was more that a similar issue should happen when installing in LPAR. LPAR
uses the line mode style console which is ttyS0 for the console but sclp_line0 for the
tty. How does the debian installer handle this?

Regarding your patch I fear that this patch would break existing setups so we cannot
use it as is.

2020-05-20 08:07:43

by Valentin Vidić

[permalink] [raw]
Subject: Re: [PATCH] s390/sclp_vt220: Fix console name to match device

On Wed, May 20, 2020 at 09:14:23AM +0200, Christian Borntraeger wrote:
> My point was more that a similar issue should happen when installing in LPAR. LPAR
> uses the line mode style console which is ttyS0 for the console but sclp_line0 for the
> tty. How does the debian installer handle this?

I suppose it would fail the same way, but I have no way to verify.

> Regarding your patch I fear that this patch would break existing
> setups so we cannot use it as is.

Right, if some software/documentation depends on the name ttysclp0,
then I guess it is not possible to change any of the two names.

--
Valentin