From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Hurley Subject: Re: [PATCH v3 2/5] tty: Introduce SER_RS485_SOFTWARE read-only flag for struct serial_rs485 Date: Thu, 3 Dec 2015 09:41:21 -0500 Message-ID: <56605491.1070206@hurleysoftware.com> References: <1447338836-8785-1-git-send-email-matwey@sai.msu.ru> <1447338836-8785-3-git-send-email-matwey@sai.msu.ru> <20151112195707.5e9cb1d8@lxorguk.ukuu.org.uk> <5644F4F2.2080408@hurleysoftware.com> <20151114152536.693d964c@lxorguk.ukuu.org.uk> <564A2BF5.8030305@hurleysoftware.com> <564CC472.8010505@hurleysoftware.com> <565F7CA2.5030505@hurleysoftware.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: "Matwey V. Kornilov" Cc: One Thousand Gnomes , Greg KH , jslaby@suse.com, linux-kernel , linux-serial@vger.kernel.org List-Id: linux-serial@vger.kernel.org Hi Matwey, On 12/03/2015 12:50 AM, Matwey V. Kornilov wrote: > I am working on v4, where I completely redesigned implementation. And > now I think that it is considerably better than v3. > It looks like the following: > https://github.com/matwey/linux/commits/8520_rs485_v4 > But it is not ready yet, there is a bug somewhere. > > In the v4, each subdriver decides separately if it needs rs485 > emulation support. Then it enables it like the following: > https://github.com/matwey/linux/commit/4455e425fc045713fb921ccec695fe183f1558f0 > Before calling serial8250_rs485_emul_enabled, the driver enables > interrupt on empty shift register (they are always there for omap_). Looks good. Are you testing with CONFIG_SERIAL_8250_DMA=n first to simplify the debug effort? DMA adds a completely different tx path. Also, before submission, please shorten the identifiers. And Greg hates functions returning bool so just expanded serial8250_rs485_emul_enabled() inline. Regards, Peter Hurley