On Wed, Sep 30, 2020 at 01:25:14PM +0200, Daniel Vetter wrote: > On Wed, Sep 30, 2020 at 12:56 PM Peilin Ye <yepeilin.cs@xxxxxxxxx> wrote: > > > > On Wed, Sep 30, 2020 at 11:53:17AM +0200, Daniel Vetter wrote: > > > On Wed, Sep 30, 2020 at 03:11:51AM -0400, Peilin Ye wrote: > > > > On Tue, Sep 29, 2020 at 04:38:49PM +0200, Daniel Vetter wrote: > > > > > On Tue, Sep 29, 2020 at 2:34 PM Peilin Ye <yepeilin.cs@xxxxxxxxx> wrote: > > > > > > Ah, and speaking of built-in fonts, see fbcon_startup(): > > > > > > > > > > > > /* Setup default font */ > > > > > > [...] > > > > > > vc->vc_font.charcount = 256; /* FIXME Need to support more fonts */ > > > > > > ^^^^^^^^^^^^^^^ > > > > > > > > > > > > This is because find_font() and get_default_font() return a `struct > > > > > > font_desc *`, but `struct font_desc` doesn't contain `charcount`. I > > > > > > think we also need to add a `charcount` field to `struct font_desc`. > > > > > > > > > > Hm yeah ... I guess maybe struct font_desc should be the starting > > > > > point for the kernel internal font structure. It's at least there > > > > > already ... > > > > > > > > I see, that will also make handling built-in fonts much easier! > > > > > > I think the only downside with starting with font_desc as the internal > > > font represenation is that there's a few fields we don't need/have for > > > userspace fonts (like the id/name stuff). So any helpers to e.g. print out > > > font information need to make sure they don't trip over that > > > > > > But otherwise I don't see a problem with this, I think. > > > > Yes, and built-in fonts don't use refcount. Or maybe we can let > > find_font() and get_default_font() kmalloc() a copy of built-in font > > data, then keep track of refcount for both user and built-in fonts, but > > that will waste a few K of memory for each built-in font we use... > > A possible trick for this would be to make sure built-in fonts start > out with a refcount of 1. So never get freed. Plus maybe a check that > if the name is set, then it's a built-in font and if we ever underflow > the refcount we just WARN, but don't free anything. > > Another trick would be kern_font_get/put wrappers (we'd want those > anyway if the userspace fonts are refcounted) and if kern_font->name > != NULL (i.e. built-in font with name) then we simply don't call > kref_get/put. Ick, don't do that, the first trick of having them start out with an increased reference count is the best way here. Makes the code simpler and no special cases for the tear-down path. thanks, greg k-h _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
