[v2,00/13] backlight: qcom-wled: fix and solidify handling of enabled-strings

Message

Marijn Suijten Oct. 7, 2021, 9:33 p.m. UTC

This patchset fixes WLED's handling of enabled-strings: besides some
cleanup it is now actually possible to specify a non-contiguous array of
enabled strings (not necessarily starting at zero) and the values from
DT are now validated to prevent possible unexpected out-of-bounds
register and array element accesses.
Off-by-one mistakes in the maximum number of strings, also causing
out-of-bounds access, have been addressed as well.

Changes in v2:
- Reordered patch 4/10 (Validate enabled string indices in DT) to sit
  before patch 1/10 (Pass number of elements to read to read_u32_array);
- Pulled qcom,num-strings out of the DT enumeration parser, and moved it
  after qcom,enabled-strings parser to always have final sign-off over
  the number of strings;
- Extra validation for this number of strings against
  qcom,enabled-strings;
- Recombined patch 9 (Consistently use enabled-strings in
  set_brightness) and patch 10 (Consider enabled_strings in
  autodetection), which both solve the same problem in two different
  functions.  In addition the autodetection code uses set_brightness as
  helper already;
- Improved DT configurations for pmi8994 and pm660l, currently in 5.15
  rc's.

v1: https://lore.kernel.org/dri-devel/[e-mail]

Marijn Suijten (13):
  backlight: qcom-wled: Validate enabled string indices in DT
  backlight: qcom-wled: Pass number of elements to read to
    read_u32_array
  backlight: qcom-wled: Use cpu_to_le16 macro to perform conversion
  backlight: qcom-wled: Fix off-by-one maximum with default num_strings
  backlight: qcom-wled: Override default length with
    qcom,enabled-strings
  backlight: qcom-wled: Remove unnecessary 4th default string in WLED3
  backlight: qcom-wled: Provide enabled_strings default for WLED 4 and 5
  backlight: qcom-wled: Remove unnecessary double whitespace
  backlight: qcom-wled: Respect enabled-strings in set_brightness
  arm64: dts: qcom: pmi8994: Fix "eternal"->"external" typo in WLED node
  arm64: dts: qcom: pmi8994: Remove hardcoded linear WLED
    enabled-strings
  arm64: dts: qcom: Move WLED num-strings from pmi8994 to
    sony-xperia-tone
  arm64: dt: qcom: pm660l: Remove board-specific WLED configuration

 .../dts/qcom/msm8996-sony-xperia-tone.dtsi    |   1 +
 arch/arm64/boot/dts/qcom/pm660l.dtsi          |   7 -
 arch/arm64/boot/dts/qcom/pmi8994.dtsi         |   5 +-
 drivers/video/backlight/qcom-wled.c           | 131 ++++++++++--------
 4 files changed, 73 insertions(+), 71 deletions(-)

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2.33.0