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

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.