Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030431AbVLGXEa (ORCPT ); Wed, 7 Dec 2005 18:04:30 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751797AbVLGXEa (ORCPT ); Wed, 7 Dec 2005 18:04:30 -0500 Received: from mx1.redhat.com ([66.187.233.31]:24234 "EHLO mx1.redhat.com") by vger.kernel.org with ESMTP id S1750886AbVLGXE3 (ORCPT ); Wed, 7 Dec 2005 18:04:29 -0500 Date: Wed, 7 Dec 2005 18:03:02 -0500 From: Dave Jones To: Xavier Bestel , Jason Dravet , linux-kernel@vger.kernel.org Subject: Re: wrong number of serial port detected Message-ID: <20051207230302.GD22690@redhat.com> Mail-Followup-To: Dave Jones , Xavier Bestel , Jason Dravet , linux-kernel@vger.kernel.org References: <20051207155034.GB6793@flint.arm.linux.org.uk> <20051207211551.GL6793@flint.arm.linux.org.uk> <1133990886.6184.2.camel@bip.parateam.prv> <20051207213128.GM6793@flint.arm.linux.org.uk> <20051207213856.GN6793@flint.arm.linux.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20051207213856.GN6793@flint.arm.linux.org.uk> User-Agent: Mutt/1.4.2.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 7476 Lines: 204 On Wed, Dec 07, 2005 at 09:38:56PM +0000, Russell King wrote: > On Wed, Dec 07, 2005 at 09:31:28PM +0000, Russell King wrote: > > On Wed, Dec 07, 2005 at 10:28:05PM +0100, Xavier Bestel wrote: > > > Le mercredi 07 d?cembre 2005 ? 21:15 +0000, Russell King a ?crit : > > > > > > > 4. User tries the well documented "setserial /dev/ttyS2 port 0x220 irq 5" > > > > procedure, which has been supported since Linux 1.x > > > > > > > > 5. User finds that, because there is no ttyS2 device in /dev, they > > > > can't configure their card. > > > > > > Well, instead of polluting everybody's /dev for the 3 users having such > > > cards, why not just tell the user to run > > > MAKEDEV /dev/ttyS2 ; setserial /dev/ttyS2 port 0x220 irq 5 > > > instead ? (Or even mknod) > > > > Oh sorry. Mail me your root password and IP address, let me log in > > to your system, and I'll remove those device nodes right now. Thanks > > for pointing that out. > > > > Seriously, surely you aren't suggesting that I somehow have personal > > control over this? > > Additionally, if you have a problem with this, the total number of > ports _is_ kernel configurable. > > So if you're getting 32 ports from a distro targetted at the current > range of consumer hardware which commonly has maybe 1 or 2 and > possibly a modem card (iow probably max 4 ports), please take it up > with them. Ok, how about something along the lines of this (completely untested) patch, which adds a runtime param to lower the number of registered ports, also allowing a default to be set for common cases. Would something like this be acceptable ? It would mean that users of kernels with NR_UARTS currently set to 32 would either also have to set the new default if they build their own kernels, or fiddle with a module param to see past their first four ports if they run a vendor kernel. Given these people are the minority use-case, adding one extra option to their modprobe.conf doesn't seem too harsh, does it ? Dave diff -urpN --exclude-from=/home/devel/davej/.exclude vanilla/drivers/serial/8250.c linux-2.6.14/drivers/serial/8250.c --- vanilla/drivers/serial/8250.c 2005-12-07 17:56:56.000000000 -0500 +++ linux-2.6.14/drivers/serial/8250.c 2005-12-07 17:51:52.000000000 -0500 @@ -54,6 +54,8 @@ */ static unsigned int share_irqs = SERIAL8250_SHARE_IRQS; +static unsigned int nr_uarts = CONFIG_SERIAL_8250_RUNTIME_UARTS; + /* * Debugging. */ @@ -2118,7 +2120,7 @@ static void __init serial8250_isa_init_p return; first = 0; - for (i = 0; i < UART_NR; i++) { + for (i = 0; i < nr_uarts; i++) { struct uart_8250_port *up = &serial8250_ports[i]; up->port.line = i; @@ -2137,7 +2139,7 @@ static void __init serial8250_isa_init_p } for (i = 0, up = serial8250_ports; - i < ARRAY_SIZE(old_serial_port) && i < UART_NR; + i < ARRAY_SIZE(old_serial_port) && i < nr_uarts; i++, up++) { up->port.iobase = old_serial_port[i].port; up->port.irq = irq_canonicalize(old_serial_port[i].irq); @@ -2159,7 +2161,7 @@ serial8250_register_ports(struct uart_dr serial8250_isa_init_ports(); - for (i = 0; i < UART_NR; i++) { + for (i = 0; i < nr_uarts; i++) { struct uart_8250_port *up = &serial8250_ports[i]; up->port.dev = dev; @@ -2262,7 +2266,7 @@ static int serial8250_console_setup(stru * if so, search for the first available port that does have * console support. */ - if (co->index >= UART_NR) + if (co->index >= nr_uarts) co->index = 0; port = &serial8250_ports[co->index].port; if (!port->iobase && !port->membase) @@ -2298,7 +2302,7 @@ static int __init find_port(struct uart_ int line; struct uart_port *port; - for (line = 0; line < UART_NR; line++) { + for (line = 0; line < nr_uarts; line++) { port = &serial8250_ports[line].port; if (p->iotype == port->iotype && p->iobase == port->iobase && @@ -2422,7 +2426,7 @@ static int __devexit serial8250_remove(s { int i; - for (i = 0; i < UART_NR; i++) { + for (i = 0; i < nr_uarts; i++) { struct uart_8250_port *up = &serial8250_ports[i]; if (up->port.dev == &dev->dev) @@ -2435,7 +2439,7 @@ static int serial8250_suspend(struct pla { int i; - for (i = 0; i < UART_NR; i++) { + for (i = 0; i < nr_uarts; i++) { struct uart_8250_port *up = &serial8250_ports[i]; if (up->port.type != PORT_UNKNOWN && up->port.dev == &dev->dev) @@ -2449,7 +2453,7 @@ static int serial8250_resume(struct plat { int i; - for (i = 0; i < UART_NR; i++) { + for (i = 0; i < nr_uarts; i++) { struct uart_8250_port *up = &serial8250_ports[i]; if (up->port.type != PORT_UNKNOWN && up->port.dev == &dev->dev) @@ -2489,7 +2493,7 @@ static struct uart_8250_port *serial8250 /* * First, find a port entry which matches. */ - for (i = 0; i < UART_NR; i++) + for (i = 0; i < nr_uarts; i++) if (uart_match_port(&serial8250_ports[i].port, port)) return &serial8250_ports[i]; @@ -2498,7 +2502,7 @@ static struct uart_8250_port *serial8250 * free entry. We look for one which hasn't been previously * used (indicated by zero iobase). */ - for (i = 0; i < UART_NR; i++) + for (i = 0; i < nr_uarts; i++) if (serial8250_ports[i].port.type == PORT_UNKNOWN && serial8250_ports[i].port.iobase == 0) return &serial8250_ports[i]; @@ -2507,7 +2511,7 @@ static struct uart_8250_port *serial8250 * That also failed. Last resort is to find any entry which * doesn't have a real port associated with it. */ - for (i = 0; i < UART_NR; i++) + for (i = 0; i < nr_uarts; i++) if (serial8250_ports[i].port.type == PORT_UNKNOWN) return &serial8250_ports[i]; @@ -2593,7 +2597,7 @@ static int __init serial8250_init(void) int ret, i; printk(KERN_INFO "Serial: 8250/16550 driver $Revision: 1.90 $ " - "%d ports, IRQ sharing %sabled\n", (int) UART_NR, + "%d ports, IRQ sharing %sabled\n", nr_uarts, share_irqs ? "en" : "dis"); for (i = 0; i < NR_IRQS; i++) @@ -2653,6 +2657,9 @@ module_param(share_irqs, uint, 0644); MODULE_PARM_DESC(share_irqs, "Share IRQs with other non-8250/16x50 devices" " (unsafe)"); +module_param(nr_uarts, uint, 0644); +MODULE_PARM_DESC(nr_uarts, "Maximum number of UARTs supported."); + #ifdef CONFIG_SERIAL_8250_RSA module_param_array(probe_rsa, ulong, &probe_rsa_count, 0444); MODULE_PARM_DESC(probe_rsa, "Probe I/O ports for RSA"); diff -urpN --exclude-from=/home/devel/davej/.exclude vanilla/drivers/serial/Kconfig linux-2.6.14/drivers/serial/Kconfig --- vanilla/drivers/serial/Kconfig 2005-12-07 17:56:56.000000000 -0500 +++ linux-2.6.14/drivers/serial/Kconfig 2005-12-07 17:53:34.000000000 -0500 @@ -95,6 +100,15 @@ config SERIAL_8250_NR_UARTS PCI enumeration and any ports that may be added at run-time via hot-plug, or any ISA multi-port serial cards. +config SERIAL_8250_RUNTIME_UARTS + int "Number of 8250/16550 serial ports to register at runtime" + depends on SERIAL_8250 + default "4" + help + Set this to the maximum number of serial ports you want + the kernel to register at boot time. This can be overriden + with the parameter "nr_uarts". + config SERIAL_8250_EXTENDED bool "Extended 8250/16550 serial driver options" depends on SERIAL_8250 - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/