From owner-svn-src-all@FreeBSD.ORG Sun Mar 31 23:24:05 2013 Return-Path: Delivered-To: svn-src-all@freebsd.org Received: from mx1.freebsd.org (mx1.FreeBSD.org [8.8.178.115]) by hub.freebsd.org (Postfix) with ESMTP id 0AC8FB9E; Sun, 31 Mar 2013 23:24:05 +0000 (UTC) (envelope-from ian@FreeBSD.org) Received: from svn.freebsd.org (svn.freebsd.org [IPv6:2001:1900:2254:2068::e6a:0]) by mx1.freebsd.org (Postfix) with ESMTP id F200C7C3; Sun, 31 Mar 2013 23:24:04 +0000 (UTC) Received: from svn.freebsd.org ([127.0.1.70]) by svn.freebsd.org (8.14.6/8.14.6) with ESMTP id r2VNO4es030737; Sun, 31 Mar 2013 23:24:04 GMT (envelope-from ian@svn.freebsd.org) Received: (from ian@localhost) by svn.freebsd.org (8.14.6/8.14.5/Submit) id r2VNO4Xd030736; Sun, 31 Mar 2013 23:24:04 GMT (envelope-from ian@svn.freebsd.org) Message-Id: <201303312324.r2VNO4Xd030736@svn.freebsd.org> From: Ian Lepore Date: Sun, 31 Mar 2013 23:24:04 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r248963 - head/sys/dev/uart X-SVN-Group: head MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 31 Mar 2013 23:24:05 -0000 Author: ian Date: Sun Mar 31 23:24:04 2013 New Revision: 248963 URL: http://svnweb.freebsd.org/changeset/base/248963 Log: Accommodate uart devices with large FIFOs (or DMA buffers which amount to the same thing) by allocating the uart(4) rx buffer based on the device's rxfifosz rather than using a hard-coded size of 384 bytes. The historical 384 byte size is 3 times the largest hard-coded fifo size in the tree, so use that ratio as a guide and allocate the buffer as three times rxfifosz, but never smaller than the historical size. Modified: head/sys/dev/uart/uart_core.c Modified: head/sys/dev/uart/uart_core.c ============================================================================== --- head/sys/dev/uart/uart_core.c Sun Mar 31 22:43:16 2013 (r248962) +++ head/sys/dev/uart/uart_core.c Sun Mar 31 23:24:04 2013 (r248963) @@ -457,7 +457,13 @@ uart_bus_attach(device_t dev) callout_init(&sc->sc_timer, 1); } - sc->sc_rxbufsz = 384; + /* + * Ensure there is room for at least three full FIFOs of data in the + * receive buffer (handles the case of low-level drivers with huge + * FIFOs), and also ensure that there is no less than the historical + * size of 384 bytes (handles the typical small-FIFO case). + */ + sc->sc_rxbufsz = MAX(384, sc->sc_rxfifosz * 3); sc->sc_rxbuf = malloc(sc->sc_rxbufsz * sizeof(*sc->sc_rxbuf), M_UART, M_WAITOK); sc->sc_txbuf = malloc(sc->sc_txfifosz * sizeof(*sc->sc_txbuf),