From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Jander Subject: Re: MCP2515 implementation is slow Date: Thu, 27 Nov 2014 08:33:46 +0100 Message-ID: <20141127083346.79d4a5af@archvile> References: <84a1d29551f84f5494b309e1ad1e0840@SGPMBX1004.APAC.bosch.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: "linux-spi@vger.kernel.org" , "linux-can@vger.kernel.org" , gianluca To: "Pankajkumar Misra (RBEI/EEA2)" Return-path: In-Reply-To: <84a1d29551f84f5494b309e1ad1e0840@SGPMBX1004.APAC.bosch.com> Sender: linux-can-owner@vger.kernel.org List-Id: linux-spi.vger.kernel.org On Tue, 25 Nov 2014 16:19:33 +0000 "Pankajkumar Misra (RBEI/EEA2)" wrote: > I have compiled MCP251x.c kernel driver module for Olimex A20-Olinuxino > Micro. > > The device is working fine for one frame at a time at 500ms. If I send two > or more frame at the same time, CAN is going to bus-off due to overrun > errors. Even if I send one frame at faster rate say, 100ms,results in > bus-off. I tend to think there is something other wrong with your setup. Maybe you are missing bus-termination/biasing? Chip-clock? The device should never go in bus-off mode if there are RX-overruns. If it goes into bus-off, there is something wrong in the hardware. > I am communicating with module with ip commands, cansend & candump. > Also my SPI module is working only at 250K baud, not any other baud. We use a MCP2515 with this driver at 250kbit/s receiving back-to-back messages without loss on a i.MX51. Please note, that it won't work reliably at any higher bitrate and system load is quite high. The MCP2515 is a very bad design, but the driver performance has improved a lot since spi-bitbang started using a kthread instead of a work-queue. > Any suggestions. > > Best Regards, > Pankaj > -- > To unsubscribe from this list: send the line "unsubscribe linux-can" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html Best regards, -- David Jander Protonic Holland.