Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932826Ab3CSPsP (ORCPT ); Tue, 19 Mar 2013 11:48:15 -0400 Received: from netrider.rowland.org ([192.131.102.5]:33725 "HELO netrider.rowland.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1756902Ab3CSPsI (ORCPT ); Tue, 19 Mar 2013 11:48:08 -0400 Date: Tue, 19 Mar 2013 11:48:07 -0400 (EDT) From: Alan Stern X-X-Sender: stern@netrider.rowland.org To: Yuan-Hsin Chen cc: Felipe Balbi , , , , , , Yuan-Hsin Chen , Subject: Re: [PATCH] usb host: Faraday FUSBH200 HCD driver. In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1195 Lines: 30 On Tue, 19 Mar 2013, Yuan-Hsin Chen wrote: > > What about the port_status registers? They're not between command and > > async_next. If they aren't consistent with EHCI, it makes things a lot > > more complicated. > > fusbh200 has only one port_status register with different offset, > 0x30, and the position of some bits are different from EHCI. That's pretty nasty. Integrating that with the standard EHCI driver would be considerably more difficult. Why was the FUSBH200 designed in this strange way? Why doesn't it use the standard EHCI register layout? Were the engineers at Faraday deliberately trying to make life harder for driver writers? > Also, usbmode_ex, hostpc, and txfill_tuning other than configured_flag > are non-existent in fusbh200. They are used in both ehci-hcd.c and > ehci-hub.c for several times. They are used only if the hardware supports them, that is, only if the ehci->has_hostpc flag is set. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/