From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ezequiel Garcia Subject: Re: [PATCH v2] serial: 8250_dw: Improve unwritable LCR workaround Date: Thu, 28 Nov 2013 16:47:21 -0300 Message-ID: <20131128194720.GD13182@localhost> References: <1380647888-32473-1-git-send-email-tim.kryger@linaro.org> <20131126183559.GA18570@localhost> <20131127185448.GA21422@localhost> <20131128093034.5d61130a@skate> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: Content-Disposition: inline In-Reply-To: <20131128093034.5d61130a@skate> 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: Thomas Petazzoni Cc: Lior Amsalem , Heikki Krogerus , Jason Cooper , Patch Tracking , Tim Kryger , Greg Kroah-Hartman , "linux-kernel@vger.kernel.org" , linux-serial@vger.kernel.org, Gregory Clement , ARM Kernel List List-Id: 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<1380647888-32473-1-git-send-email-tim.kryger@linaro.org> <20131126183559.GA18570@localhost> <20131127185448.GA21422@localhost> <20131128093034.5d61130a@skate> Message-ID: <20131128194720.GD13182@localhost> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi Thomas, Tim: On Thu, Nov 28, 2013 at 09:30:34AM +0100, Thomas Petazzoni wrote: > Dear Ezequiel Garcia, > > On Wed, 27 Nov 2013 15:54:49 -0300, Ezequiel Garcia wrote: > > > > An external device may be keeping the UART busy and preventing LCR > > > from being written. > > > > > > What device is attached to ttyS1? > > > > There's no device attached at ttyS1. I've just tested this in another > > box and it seems the same error is obtained on each unused port: > > Are you sure about this? I suppose you're testing on the Armada XP GP > board, and this board has a 4 ports FTDI chip, and according to the > board schematics the four UARTs are all connected to the FTDI chip. So > from the SoC perspective, ttyS1 is connected to something, as far as I > can understand. Or maybe you also tested Armada XP DB ? > Yeah, sorry about that. I missed the FTDI chip. As Thomas says the XP GP board I'm testing this on, has its four UARTs connected to a FTDI chip. Changing the console port by setting "console=ttyS1,115200" gives this: [..] Serial: 8250/16550 driver, 4 ports, IRQ sharing enabled dw-apb-uart d0012000.serial: Couldn't set LCR to 191 dw-apb-uart d0012000.serial: Couldn't set LCR to 191 dw-apb-uart d0012000.serial: Couldn't set LCR to 224 dw-apb-uart d0012000.serial: Couldn't set LCR to 224 d0012000.serial: ttyS0 at MMIO 0xd0012000 (irq = 17, base_baud = 15625000) is a 16550A dw-apb-uart d0012100.serial: Couldn't set LCR to 191 dw-apb-uart d0012100.serial: Couldn't set LCR to 191 dw-apb-uart d0012100.serial: Couldn't set LCR to 224 dw-apb-uart d0012100.serial: Couldn't set LCR to 224 d0012100.serial: ttyS1 at MMIO 0xd0012100 (irq = 18, base_baud = 15625000) is a 16550A console [ttyS1] enabled dw-apb-uart d0012200.serial: Couldn't set LCR to 191 dw-apb-uart d0012200.serial: Couldn't set LCR to 191 dw-apb-uart d0012200.serial: Couldn't set LCR to 224 dw-apb-uart d0012200.serial: Couldn't set LCR to 224 d0012200.serial: ttyS2 at MMIO 0xd0012200 (irq = 31, base_baud = 15625000) is a 16550A dw-apb-uart d0012300.serial: Couldn't set LCR to 191 dw-apb-uart d0012300.serial: Couldn't set LCR to 191 dw-apb-uart d0012300.serial: Couldn't set LCR to 224 dw-apb-uart d0012300.serial: Couldn't set LCR to 224 d0012300.serial: ttyS3 at MMIO 0xd0012300 (irq = 32, base_baud = 15625000) is a 16550A So we get the "Couldn't set" message in all four ports. Tim: Any ideas? -- Ezequiel Garc?a, Free Electrons Embedded Linux, Kernel and Android Engineering http://free-electrons.com From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758967Ab3K1Tr4 (ORCPT ); Thu, 28 Nov 2013 14:47:56 -0500 Received: from top.free-electrons.com ([176.31.233.9]:39040 "EHLO mail.free-electrons.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751045Ab3K1Try (ORCPT ); Thu, 28 Nov 2013 14:47:54 -0500 Date: Thu, 28 Nov 2013 16:47:21 -0300 From: Ezequiel Garcia To: Thomas Petazzoni Cc: Tim Kryger , Greg Kroah-Hartman , Heikki Krogerus , linux-serial@vger.kernel.org, "linux-kernel@vger.kernel.org" , Patch Tracking , Gregory Clement , Lior Amsalem , Jason Cooper , ARM Kernel List Subject: Re: [PATCH v2] serial: 8250_dw: Improve unwritable LCR workaround Message-ID: <20131128194720.GD13182@localhost> References: <1380647888-32473-1-git-send-email-tim.kryger@linaro.org> <20131126183559.GA18570@localhost> <20131127185448.GA21422@localhost> <20131128093034.5d61130a@skate> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20131128093034.5d61130a@skate> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Thomas, Tim: On Thu, Nov 28, 2013 at 09:30:34AM +0100, Thomas Petazzoni wrote: > Dear Ezequiel Garcia, > > On Wed, 27 Nov 2013 15:54:49 -0300, Ezequiel Garcia wrote: > > > > An external device may be keeping the UART busy and preventing LCR > > > from being written. > > > > > > What device is attached to ttyS1? > > > > There's no device attached at ttyS1. I've just tested this in another > > box and it seems the same error is obtained on each unused port: > > Are you sure about this? I suppose you're testing on the Armada XP GP > board, and this board has a 4 ports FTDI chip, and according to the > board schematics the four UARTs are all connected to the FTDI chip. So > from the SoC perspective, ttyS1 is connected to something, as far as I > can understand. Or maybe you also tested Armada XP DB ? > Yeah, sorry about that. I missed the FTDI chip. As Thomas says the XP GP board I'm testing this on, has its four UARTs connected to a FTDI chip. Changing the console port by setting "console=ttyS1,115200" gives this: [..] Serial: 8250/16550 driver, 4 ports, IRQ sharing enabled dw-apb-uart d0012000.serial: Couldn't set LCR to 191 dw-apb-uart d0012000.serial: Couldn't set LCR to 191 dw-apb-uart d0012000.serial: Couldn't set LCR to 224 dw-apb-uart d0012000.serial: Couldn't set LCR to 224 d0012000.serial: ttyS0 at MMIO 0xd0012000 (irq = 17, base_baud = 15625000) is a 16550A dw-apb-uart d0012100.serial: Couldn't set LCR to 191 dw-apb-uart d0012100.serial: Couldn't set LCR to 191 dw-apb-uart d0012100.serial: Couldn't set LCR to 224 dw-apb-uart d0012100.serial: Couldn't set LCR to 224 d0012100.serial: ttyS1 at MMIO 0xd0012100 (irq = 18, base_baud = 15625000) is a 16550A console [ttyS1] enabled dw-apb-uart d0012200.serial: Couldn't set LCR to 191 dw-apb-uart d0012200.serial: Couldn't set LCR to 191 dw-apb-uart d0012200.serial: Couldn't set LCR to 224 dw-apb-uart d0012200.serial: Couldn't set LCR to 224 d0012200.serial: ttyS2 at MMIO 0xd0012200 (irq = 31, base_baud = 15625000) is a 16550A dw-apb-uart d0012300.serial: Couldn't set LCR to 191 dw-apb-uart d0012300.serial: Couldn't set LCR to 191 dw-apb-uart d0012300.serial: Couldn't set LCR to 224 dw-apb-uart d0012300.serial: Couldn't set LCR to 224 d0012300.serial: ttyS3 at MMIO 0xd0012300 (irq = 32, base_baud = 15625000) is a 16550A So we get the "Couldn't set" message in all four ports. Tim: Any ideas? -- Ezequiel García, Free Electrons Embedded Linux, Kernel and Android Engineering http://free-electrons.com