Hi Jonas,

On Tue, Jul 18, 2017 at 12:17 PM, Jonas Gorski [off-list ref] wrote:

The common clock and several other clock API implementations allow
calling clk_get_rate with a NULL pointer. While not specified as
expected behavior of the API, device drivers have come to rely on that,
causing them to OOPS when run on a platform with a different clock API
implementation.

Fix this by making sure all clk_get_rate implementations handle
NULL clocks instead of OOPSing.

While some custom implementations even allow ERR_PTR()s, I decided
against that as IIRC the usual idea is that errors should be handled and
not silently carried over.

Cc: adi-buildroot-devel at lists.sourceforge.net
Cc: bcm-kernel-feedback-list at broadcom.com
Cc: linux-arm-kernel at lists.infradead.org
Cc: linux-kernel at vger.kernel.org
Cc: linux-m68k at lists.linux-m68k.org
Cc: linux-mips at linux-mips.org

Jonas Gorski (9):
  ARM: ep93xx: allow NULL clock for clk_get_rate
  ARM: mmp: allow NULL clock for clk_get_rate
  blackfin: bf609: allow NULL clock for clk_get_rate
  m68k: allow NULL clock for clk_get_rate
  MIPS: AR7: allow NULL clock for clk_get_rate
  MIPS: BCM63XX: allow NULL clock for clk_get_rate
  MIPS: Loongson 2F: allow NULL clock for clk_get_rate
  MIPS: ralink: allow NULL clock for clk_get_rate
  unicore32: allow NULL clock for clk_get_rate

 arch/arm/mach-ep93xx/clock.c           | 3 +++
 arch/arm/mach-mmp/clock.c              | 4 +++-
 arch/blackfin/mach-bf609/clock.c       | 2 +-
 arch/m68k/coldfire/clk.c               | 3 +++
 arch/mips/ar7/clock.c                  | 3 +++
 arch/mips/bcm63xx/clk.c                | 3 +++
 arch/mips/loongson64/lemote-2f/clock.c | 3 +++
 arch/mips/ralink/clk.c                 | 3 +++
 arch/unicore32/kernel/clock.c          | 3 +++
 9 files changed, 25 insertions(+), 2 deletions(-)

For the whole series:
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert at linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds