From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ivan Ivanov Subject: Re: regression: 3a878c430fd6 ("tty: serial: msm: Add TX DMA support") drops data Date: Wed, 20 Apr 2016 09:07:19 +0300 Message-ID: References: <5716BDF1.1010407@gmail.com> Mime-Version: 1.0 (Mac OS X Mail 9.3 \(3124\)) Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from mail-wm0-f66.google.com ([74.125.82.66]:32980 "EHLO mail-wm0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750859AbcDTGHY convert rfc822-to-8bit (ORCPT ); Wed, 20 Apr 2016 02:07:24 -0400 In-Reply-To: <5716BDF1.1010407@gmail.com> Sender: linux-arm-msm-owner@vger.kernel.org List-Id: linux-arm-msm@vger.kernel.org To: frowand.list@gmail.com Cc: Andy Gross , David Brown , srinivas.kandagatla@linaro.org, Greg Kroah-Hartman , jslaby@suse.com, Rob Herring , Pawel Moll , Mark Rutland , Ian Campbell , "devicetree@vger.kernel.org" , Linux Kernel list , "linux-arm-msm@vger.kernel.org" , linux-soc@vger.kernel.org, linux-serial@vger.kernel.org > On Apr 20, 2016, at 02:23, Frank Rowand wrot= e: >=20 > Hi Ivan, >=20 > It appears that I have found a regression caused by > 3a878c430fd6 ("tty: serial: msm: Add TX DMA support"). >=20 > When I cat a file slightly larger than 126000 bytes on > the console, viewed via minicom connected to the serial > port, I am losing random chunks of data, almost always > three bytes in length. I have also seen a lost chunk > of two bytes. >=20 > I am using the 8074 dragonboard, with the dts of > arch/arm/boot/dts/qcom-apq8074-dragonboard.dts. > The dts node is serial@f991e000, which has a > compatible of "qcom,msm-uartdm-v1.4", so is_uartdm > should be UARTDM_1P4. I don=E2=80=99t remember what was biggest chunk, which DMA could carry, sorry. Are you using DMA or just PIO?=20 Is this happening only with cat and terminal or even when you send data in other means. I believe that=20 people from Linaro could help you better. Regards, Ivan-- To unsubscribe from this list: send the line "unsubscribe linux-arm-msm= " in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html