On Mon, Feb 26, 2024 at 07:58:54PM +0200, Jani Nikula wrote:
> Add a function to return the expected child device size. Flip the if
> ladder around and use the same versions as in documentation to make it
> easier to verify. Return an error for unknown versions. No functional
> changes.
>
> v2: Move BUILD_BUG_ON() next to the expected sizes
>
> Signed-off-by: Jani Nikula <jani.nikula@xxxxxxxxx>
> ---
> drivers/gpu/drm/i915/display/intel_bios.c | 40 ++++++++++++++---------
> 1 file changed, 24 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_bios.c b/drivers/gpu/drm/i915/display/intel_bios.c
> index c0f41bd1f946..343726de9aa7 100644
> --- a/drivers/gpu/drm/i915/display/intel_bios.c
> +++ b/drivers/gpu/drm/i915/display/intel_bios.c
> @@ -2699,27 +2699,35 @@ static void parse_ddi_ports(struct drm_i915_private *i915)
> print_ddi_port(devdata);
> }
>
> +static int child_device_expected_size(u16 version)
> +{
> + BUILD_BUG_ON(sizeof(struct child_device_config) < 40);
Should we make that !=40 perhaps?
Anyways, series is
Reviewed-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
> +
> + if (version > 256)
> + return -ENOENT;
> + else if (version >= 256)
> + return 40;
> + else if (version >= 216)
> + return 39;
> + else if (version >= 196)
> + return 38;
> + else if (version >= 195)
> + return 37;
> + else if (version >= 111)
> + return LEGACY_CHILD_DEVICE_CONFIG_SIZE;
> + else if (version >= 106)
> + return 27;
> + else
> + return 22;
> +}
> +
> static bool child_device_size_valid(struct drm_i915_private *i915, int size)
> {
> int expected_size;
>
> - if (i915->display.vbt.version < 106) {
> - expected_size = 22;
> - } else if (i915->display.vbt.version < 111) {
> - expected_size = 27;
> - } else if (i915->display.vbt.version < 195) {
> - expected_size = LEGACY_CHILD_DEVICE_CONFIG_SIZE;
> - } else if (i915->display.vbt.version == 195) {
> - expected_size = 37;
> - } else if (i915->display.vbt.version <= 215) {
> - expected_size = 38;
> - } else if (i915->display.vbt.version <= 255) {
> - expected_size = 39;
> - } else if (i915->display.vbt.version <= 256) {
> - expected_size = 40;
> - } else {
> + expected_size = child_device_expected_size(i915->display.vbt.version);
> + if (expected_size < 0) {
> expected_size = sizeof(struct child_device_config);
> - BUILD_BUG_ON(sizeof(struct child_device_config) < 40);
> drm_dbg(&i915->drm,
> "Expected child device config size for VBT version %u not known; assuming %d\n",
> i915->display.vbt.version, expected_size);
> --
> 2.39.2
--
Ville Syrjälä
Intel
