[PATCH v1 0/1] Fix MAPML calculation in ap bus code

[PATCH v1 0/1] Fix MAPML calculation in ap bus code

[Finn Callies]

Pretty self explanatory...

====== CHANGELOG ======

v1:
    initial version

Finn Callies (1):
  s390/ap: Fix MAPML computation

 drivers/s390/crypto/ap_card.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

-- 
Finn Callies <fcallies@linux.ibm.com>
Linux on Z - crypto

[PATCH v1 1/1] s390/ap: Fix MAPML computation

[Finn Callies]

When the TAPQ subfunction of PQAP returns a value between 0 and 3 in the
ml field the Principles of Operation states that the MAPML size is to be
12k bytes.

Reviewed-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Finn Callies <fcallies@linux.ibm.com>
---
 drivers/s390/crypto/ap_card.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/s390/crypto/ap_card.c b/drivers/s390/crypto/ap_card.c
index e827fbeb76fb..c86397f4ddcd 100644
--- a/drivers/s390/crypto/ap_card.c
+++ b/drivers/s390/crypto/ap_card.c
@@ -241,7 +241,7 @@ struct ap_card *ap_card_create(int id, struct ap_tapq_hwinfo hwinfo,
 	ac->ap_dev.device_type = comp_type;
 	ac->hwinfo = hwinfo;
 	ac->id = id;
-	ac->maxmsgsize = hwinfo.ml > 0 ?
+	ac->maxmsgsize = hwinfo.ml > 3 ?
 		hwinfo.ml * AP_TAPQ_ML_FIELD_CHUNK_SIZE : AP_DEFAULT_MAX_MSG_SIZE;
 
 	return ac;
-- 
Finn Callies <fcallies@linux.ibm.com>
Linux on Z - crypto

Re: [PATCH v1 1/1] s390/ap: Fix MAPML computation

[sashiko-bot]

> When the TAPQ subfunction of PQAP returns a value between 0 and 3 in the
> ml field the Principles of Operation states that the MAPML size is to be
> 12k bytes.
> 
> Reviewed-by: Harald Freudenberger <freude@linux.ibm.com>
> Signed-off-by: Finn Callies <fcallies@linux.ibm.com>

Sashiko has reviewed this patch and found no issues. It looks great!

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260804105811.17744-2-fcallies@linux.ibm.com?part=1

Re: [PATCH v1 1/1] s390/ap: Fix MAPML computation

[Heiko Carstens]

On Tue, Aug 04, 2026 at 12:58:11PM +0200, Finn Callies wrote:
> When the TAPQ subfunction of PQAP returns a value between 0 and 3 in the
> ml field the Principles of Operation states that the MAPML size is to be
> 12k bytes.

What is "MAPML"?

> Reviewed-by: Harald Freudenberger <freude@linux.ibm.com>
> Signed-off-by: Finn Callies <fcallies@linux.ibm.com>
> ---
>  drivers/s390/crypto/ap_card.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

Why is this fix required? What does this fix?
Are there user observable bugs fixed with this?
If so, which ones?
Is a Fixes: and/or stable tag required?

Re: [PATCH v1 0/1] Fix MAPML calculation in ap bus code

[Heiko Carstens]

On Tue, Aug 04, 2026 at 12:58:10PM +0200, Finn Callies wrote:
> Pretty self explanatory...
> 
> ====== CHANGELOG ======
> 
> v1:
>     initial version

You don't need to provide a cover-letter for a single patch, however
if you provide a cover-letter, then please provide meaningful text.

"Pretty self explanatory..." is not helpful at all.