From mboxrd@z Thu Jan 1 00:00:00 1970 From: Russell King - ARM Linux Subject: Re: 4.16 OMAP serial transmit corruption? Date: Mon, 16 Apr 2018 18:48:26 +0100 Message-ID: <20180416174826.GJ10990@n2100.armlinux.org.uk> References: <20180416151732.GU16141@n2100.armlinux.org.uk> <20180416155259.GB5671@atomide.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <20180416155259.GB5671@atomide.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: Tony Lindgren Cc: Greg Kroah-Hartman , linux-omap@vger.kernel.org, linux-serial@vger.kernel.org, linux-arm-kernel@lists.infradead.org List-Id: linux-omap@vger.kernel.org On Mon, Apr 16, 2018 at 08:52:59AM -0700, Tony Lindgren wrote: > * Russell King - ARM Linux [180416 15:19]: > > Since this uses a USB adapter (built onto the board) it could be > > that there could be a bug in the driver for that rather than the > > OMAP4430 SDP, but I've no way to check that hypothesis. > > Does it go away when you do a warm reboot of the sdp? Then > it should not be related to the USB iff the ftdi chip is bus > powered by VBUS. Yes, the FTDI chip is bus powered. I booted, ran vi, quit vi, saw corruption, typed reboot, waited for it to reboot, ran vi, quit vi, and still saw corruption. So the reboot seems to have had no effect. I don't see it with other USB serial consoles on other machines... I have two of these using the same FTDI chipset: Bus 001 Device 021: ID 0403:6011 Future Technology Devices International, Ltd FT4232H Quad HS USB-UART/FIFO IC Bus 001 Device 020: ID 0403:6011 Future Technology Devices International, Ltd FT4232H Quad HS USB-UART/FIFO IC Device 20 is the SDP board, and device 21 is a ZII board. Both use port 2 on the quad ftdi device. The serial console on the ZII board is fine, so that seems to rule out the FTDI driver / FTDI hardware. -- RMK's Patch system: http://www.armlinux.org.uk/developer/patches/ FTTC broadband for 0.8mile line in suburbia: sync at 8.8Mbps down 630kbps up According to speedtest.net: 8.21Mbps down 510kbps up