From mboxrd@z Thu Jan 1 00:00:00 1970 From: Igor Plyatov Subject: spi-atmel.c: regression Date: Mon, 2 Oct 2017 17:45:07 +0300 Message-ID: <0876ce0a-cb93-07b7-8019-e365d08cca2a@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit To: Nicolas Ferre , Mark Brown , linux-spi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Cyrille Pitchen Return-path: Content-Language: en-US Sender: linux-spi-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: Hello! please help to manage issue with data corruption by PDC of SPI. I have compared operation of Linux-2.6.39 and linux4sam kernel 4.9.36+ on the AT91SAM9G20 (Stamp9G20 SOM from Taskit.de) and found regression in the spi-atmel.c. New spi-atmel.c driver works very bad with SPI speeds above 6 MHz. I see corruption in data received by Linux and SPI overruns when OS has big CPI and IO load. Old kernel works fine at 22 MHz with the same device driver and hardware. Can somebody comment and/or help on how to resolve this issue? Best wishes. -- Igor Plyatov -- To unsubscribe from this list: send the line "unsubscribe linux-spi" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751672AbdJBOpM (ORCPT ); Mon, 2 Oct 2017 10:45:12 -0400 Received: from mail-lf0-f45.google.com ([209.85.215.45]:49465 "EHLO mail-lf0-f45.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750957AbdJBOpK (ORCPT ); Mon, 2 Oct 2017 10:45:10 -0400 X-Google-Smtp-Source: AOwi7QDlMYIUE0ZvMUNpHj0R2deJzutLbUUsPCQH20ZgH7M7PnVM6ojtZByi5ZWKngiEt7ee7+oBfA== From: Igor Plyatov Subject: spi-atmel.c: regression To: Nicolas Ferre , Mark Brown , linux-spi@vger.kernel.org, linux-kernel@vger.kernel.org, Cyrille Pitchen Message-ID: <0876ce0a-cb93-07b7-8019-e365d08cca2a@gmail.com> Date: Mon, 2 Oct 2017 17:45:07 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.2.1 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello! please help to manage issue with data corruption by PDC of SPI. I have compared operation of Linux-2.6.39 and linux4sam kernel 4.9.36+ on the AT91SAM9G20 (Stamp9G20 SOM from Taskit.de) and found regression in the spi-atmel.c. New spi-atmel.c driver works very bad with SPI speeds above 6 MHz. I see corruption in data received by Linux and SPI overruns when OS has big CPI and IO load. Old kernel works fine at 22 MHz with the same device driver and hardware. Can somebody comment and/or help on how to resolve this issue? Best wishes. -- Igor Plyatov