On Mon, Sep 23, 2024 at 05:24:46PM +0300, Jani Nikula wrote: > On Mon, 23 Sep 2024, Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> wrote: > > On Mon, Sep 23, 2024 at 12:12:39PM +0300, Jani Nikula wrote: > >> On Fri, 20 Sep 2024, Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> wrote: > >> > On Thu, Sep 12, 2024 at 03:15:52PM +0300, Jani Nikula wrote: > >> >> On Tue, 10 Sep 2024, Ville Syrjala <ville.syrjala@xxxxxxxxxxxxxxx> wrote: > >> >> > From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > >> >> > > >> >> > Replace the three hand rolled "$VBT"s with a vbt_signature[] > >> >> > to avoid accidents. > >> >> > > >> >> > Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > >> >> > --- > >> >> > drivers/gpu/drm/i915/display/intel_bios.c | 12 +++++++++--- > >> >> > 1 file changed, 9 insertions(+), 3 deletions(-) > >> >> > > >> >> > diff --git a/drivers/gpu/drm/i915/display/intel_bios.c b/drivers/gpu/drm/i915/display/intel_bios.c > >> >> > index cbbda94c3dab..0b92b494117f 100644 > >> >> > --- a/drivers/gpu/drm/i915/display/intel_bios.c > >> >> > +++ b/drivers/gpu/drm/i915/display/intel_bios.c > >> >> > @@ -2964,6 +2964,8 @@ static const struct bdb_header *get_bdb_header(const struct vbt_header *vbt) > >> >> > return _vbt + vbt->bdb_offset; > >> >> > } > >> >> > > >> >> > +static const char vbt_signature[4] = "$VBT"; > >> >> > >> >> Always a bit scary to add strings without termination, but I guess it's > >> >> justified here. > >> > > >> > I guess we could make it look less like a string with eg. > >> > static const u8 vbt_signature[] = { '$', 'V', 'B', 'T' }; > >> > ? > >> > >> Alternatively, > >> > >> static const char *vbt_signature = "$VBT"; > > > > Or could just be something like: > > > > static const char vbt_signature[] = "$VBT"; > > static const int vbt_signature_len = 4; > > > > BUILD_BUG_ON(vbt_signature_len != sizeof(vbt_signature) - 1); > > BUILD_BUG_ON(vbt_signature_len != sizeof(u32)); > > > > and use vbt_signature_len instead sizeof(vbt_signature) everwhere. > > Works for me, up to you. I'll roll with that. I guess it's safer to have the '\0' in case someone gets the urge to do something like printk("Unable to find %s ...\n", vbt_signature) etc. -- Ville Syrjälä Intel