drm/ast: Remove little-endianism from I/O helpers

Replace one call to ast_io_write16() with two calls to ast_io_write8()
in ast_set_index_reg(). The combined 16-bit-wide write of an index
register and the corresponding data register only works on little-
endian systems. Write both registers independent from each other.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230221155745.27484-2-tzimmermann@suse.de

diff --git a/drivers/gpu/drm/ast/ast_drv.h b/drivers/gpu/drm/ast/ast_drv.h
index d51b81f..1f46162 100644 (file)
--- a/drivers/gpu/drm/ast/ast_drv.h
+++ b/drivers/gpu/drm/ast/ast_drv.h
@@ -282,7 +282,9 @@ static inline void ast_set_index_reg(struct ast_private *ast,
                                     uint32_t base, uint8_t index,
                                     uint8_t val)
 {
-       ast_io_write16(ast, base, ((u16)val << 8) | index);
+       ast_io_write8(ast, base, index);
+       ++base;
+       ast_io_write8(ast, base, val);
 }
 
 void ast_set_index_reg_mask(struct ast_private *ast,