From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.0 required=3.0 tests=BAYES_00,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BA3D5C433DB for ; Fri, 8 Jan 2021 13:31:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7BB7D2396F for ; Fri, 8 Jan 2021 13:31:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726992AbhAHNaz convert rfc822-to-8bit (ORCPT ); Fri, 8 Jan 2021 08:30:55 -0500 Received: from mail.kernel.org ([198.145.29.99]:36320 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726060AbhAHNaz (ORCPT ); Fri, 8 Jan 2021 08:30:55 -0500 Received: by mail.kernel.org (Postfix) with ESMTPS id 70686235FF for ; Fri, 8 Jan 2021 13:30:14 +0000 (UTC) From: bugzilla-daemon@bugzilla.kernel.org To: linux-usb@vger.kernel.org Subject: [Bug 210351] Wrong setting baudrate for FTDI chip FT230X Date: Fri, 08 Jan 2021 13:30:14 +0000 X-Bugzilla-Reason: None X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: AssignedTo drivers_usb@kernel-bugs.kernel.org X-Bugzilla-Product: Drivers X-Bugzilla-Component: USB X-Bugzilla-Version: 2.5 X-Bugzilla-Keywords: X-Bugzilla-Severity: high X-Bugzilla-Who: johan@kernel.org X-Bugzilla-Status: NEW X-Bugzilla-Resolution: X-Bugzilla-Priority: P1 X-Bugzilla-Assigned-To: drivers_usb@kernel-bugs.kernel.org X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8BIT X-Bugzilla-URL: https://bugzilla.kernel.org/ Auto-Submitted: auto-generated MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org https://bugzilla.kernel.org/show_bug.cgi?id=210351 --- Comment #3 from Johan Hovold (johan@kernel.org) --- On Fri, Jan 08, 2021 at 11:37:13AM +0000, bugzilla-daemon@bugzilla.kernel.org wrote: > Unfortunately, I don't have a device at hand right now. But I remember the > lsusb output was showing FT-X type. And under Windows, all three chips I > mentioned work correctly with all prescalers. I contacted FTDI tech support > with this problem. They advised me to have such a patch for ftdi_sio.c and it > solved the problem. Here's the patch: > if ((priv-> chip_type == FT2232C) || (priv-> chip_type == FT2232H) || > > (priv-> chip_type == FT4232H) || (priv-> chip_type == FT232H) || > > (priv-> chip_type == FTX)) { > > / * Probably the BM type needs the MSB of the encoded fractional > > * divider also moved like for the chips above. Any infos? * / > > index = (u16) ((index << 8) | priv-> interface); > > } Ah, that's good to hear. Do you want to submit that as a proper patch that I can apply, or do you want me to do that? > But I don't know why the most significant bit of the prescaler is masked by > something. I have no information about the chip configuration registers. It > looks like this is confidential information. But they could provide it to you > as the driver developer. I don't have access to any details about these chips apart from the public sources either, I'm afraid. But here it seems the upper bits simply needs to be shifted to make room for the interface number just like for the H-types (which can have more than one port). Johan -- You may reply to this email to add a comment. You are receiving this mail because: You are watching the assignee of the bug.