From mboxrd@z Thu Jan 1 00:00:00 1970 From: Timur Tabi Date: Thu, 15 Dec 2011 22:10:42 +0000 Subject: Re: Should I use FBINFO_VIRTFB? Message-Id: <4EEA7062.9050807@freescale.com> List-Id: References: <4EEA5DA7.3010406@freescale.com> In-Reply-To: <4EEA5DA7.3010406@freescale.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-fbdev@vger.kernel.org Konrad Rzeszutek Wilk wrote: >> > #define FBINFO_PARTIAL_PAN_OK 0x0040 /* otw use pan only for double-buffering */ >> > #define FBINFO_READS_FAST 0x0080 /* soft-copy faster than rendering */ > Not really. They have a different function, but you are better of looking in the code > to see how they are used. Well, I tried that, which is why I said, "I don't see any good documentation." FBINFO_PARTIAL_PAN_OK appears to be only used in one place: case SCROLL_PAN_REDRAW: if ((p->yscroll + count < 2 * (p->vrows - vc->vc_rows)) && ((!scroll_partial && (b - t = vc->vc_rows)) || (scroll_partial && (b - t - count > 3 * vc->vc_rows >> 2)))) { if (t > 0) fbcon_redraw_move(vc, p, 0, t, count); ypan_up_redraw(vc, t, count); if (vc->vc_rows - b > 0) fbcon_redraw_move(vc, p, b, vc->vc_rows - b, b); } else fbcon_redraw_move(vc, p, t + count, b - t - count, t); fbcon_clear(vc, b - count, 0, count, vc->vc_cols); break; I can't parse this, and I can't figure out if my driver is better off with or without FBINFO_PARTIAL_PAN_OK. I have the same problem with FBINFO_READS_FAST. So I really would like someone explain these macros to me. -- Timur Tabi Linux kernel developer at Freescale