[Linux-fbdev-devel] Re: [TRIVIAL PATCH] FBDEV: Small impact patch for fbdev

[James S. <jsi...@in...>]

> Here's a diff to correct several small things that escaped through the
> cracks.

Ug. Now that a wider test base is being done and more drivers actually
compile we are going to see more cracks.

> 1.  The YNOMOVE scrollmode for non-accelerated drivers is just very slow
> because of a lot of block moves (leads to slow and jerky scrolling in
> vesafb with ypanning enabled).  Depending on var->accel_flags, set the
> scrollmode to either YREDRAW or YNOMOVE. For drivers with hardware
> acceleration, set var->accel_flags to nonzero for max speed.

Thanks. I have had several emails complementing the speed improvements.
Another speed boost will be a plus.

> 2.  fb_pan_display() always returns an error.  User apps will complain.

Fixed. Actually I used the following code.

int fb_pan_display(struct fb_var_screeninfo *var, struct fb_info *info)
{
        int xoffset = var->xoffset;
        int yoffset = var->yoffset;
        int err;

        if (xoffset < 0 || yoffset < 0 || info->fbops->fb_pan_display ||
            xoffset + info->var.xres > info->var.xres_virtual ||
            yoffset + info->var.yres > info->var.yres_virtual)
                return -EINVAL;
        if ((err = info->fbops->fb_pan_display(var, info)))
                return err;
        info->var.xoffset = var->xoffset;
        info->var.yoffset = var->yoffset;
        if (var->vmode & FB_VMODE_YWRAP)

instead. The reason is I didn't like the idea of xoffset and yoffset being
changed even if the hardware panning function failed. Comments?

> 3.  case FBIO_GETCMAP in fb_ioctl does not return immediately.  User
> apps will complain.

Fixed.

> 4.  vgastate.c is not saving the correct blocks.

Fixed.

> 5.  logo drawing for monochrome displays is just incorrect.(alterations
> were done by eyeballing only, no hardware for testing).

Will test on hgafb driver.