[PATCH v2 0/2] vsprintf: remove redundant %pCn format specifier

From: Luca Ceresoli
Date: Tue Mar 11 2025 - 05:21:51 EST


There are two printk format specifiers for clocks: %pC and %pCn, and they
print exactly the same string. Geert confirmed the intended reason for
having two was that %pC would act as a default, like some (but not all)
formats do. However there seem to be no advantage in having two instead of
one, especially now that there is no other %pC specifier since commit
666902e42fd8 ("lib/vsprintf: Remove atomic-unsafe support for %pCr").

Definitely having two without properly documenting they do the same creates
misunderstandings [0].

Since %pCn is used in a single place, replace it with %pC and remove %pCn
to simplify such format specifiers implementation and avoid
misunderstandings.

[0] https://lore.kernel.org/dri-devel/f8df2b5e-b005-4ada-8108-159b2b94a72e@xxxxxxx/

Signed-off-by: Luca Ceresoli <luca.ceresoli@xxxxxxxxxxx>
---
Changes in v2:
- Add Chinese translation
- Link to v1: https://lore.kernel.org/r/20250307-vsprintf-pcn-v1-0-df0b2ccf610f@xxxxxxxxxxx

---
Luca Ceresoli (2):
thermal: bcm2835: use %pC instead of %pCn
vsprintf: remove redundant and unused %pCn format specifier

Documentation/core-api/printk-formats.rst | 3 +--
Documentation/translations/zh_CN/core-api/printk-formats.rst | 3 +--
drivers/thermal/broadcom/bcm2835_thermal.c | 2 +-
lib/vsprintf.c | 10 ++--------
4 files changed, 5 insertions(+), 13 deletions(-)
---
base-commit: 4d872d51bc9d7b899c1f61534e3dbde72613f627
change-id: 20250307-vsprintf-pcn-8a43e3b0d43e

Best regards,
--
Luca Ceresoli <luca.ceresoli@xxxxxxxxxxx>