Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754013AbZGTUJg (ORCPT ); Mon, 20 Jul 2009 16:09:36 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753386AbZGTUJf (ORCPT ); Mon, 20 Jul 2009 16:09:35 -0400 Received: from mail.windriver.com ([147.11.1.11]:36138 "EHLO mail.wrs.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753143AbZGTUJc (ORCPT ); Mon, 20 Jul 2009 16:09:32 -0400 From: Jason Wessel To: gregkh@suse.de Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, Jason Wessel , Ingo Molnar , Andrew Morton , Yinghai Lu , "Eric W. Biederman" Subject: [PATCH 04/10] usb,early_printk: EHCI debug controller initialization delays Date: Mon, 20 Jul 2009 15:06:26 -0500 Message-Id: <1248120392-8372-5-git-send-email-jason.wessel@windriver.com> X-Mailer: git-send-email 1.6.0.3.523.g304d0 In-Reply-To: <1248120392-8372-4-git-send-email-jason.wessel@windriver.com> References: <1248120392-8372-1-git-send-email-jason.wessel@windriver.com> <1248120392-8372-2-git-send-email-jason.wessel@windriver.com> <1248120392-8372-3-git-send-email-jason.wessel@windriver.com> <1248120392-8372-4-git-send-email-jason.wessel@windriver.com> X-OriginalArrivalTime: 20 Jul 2009 20:06:40.0926 (UTC) FILETIME=[9895D3E0:01CA0975] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4545 Lines: 152 When using the EHCI host controller as a polled device, a bit more tolerance is required in terms of delays. On some 3+ghz systems the cpu loops were faster than the EHCI device mmio and resulted in the controller failing to initialize. On at least one first generation EHCI controller when it was not operating in interrupt mode, it would fail to report a port change status, but executing the port reset allowed the debug controller to work correctly anyway. This errata causes a one time 300ms delay in the boot time, where as the typical delay is 1-5ms for an EHCI controller that does not have this errata. The debug printk's were fixed to have the correct state messages, and there was a conversion from using early_printk to printk to avoid calling the dbgp driver while debugging the initialization. Signed-off-by: Jason Wessel Cc: Greg KH Cc: Ingo Molnar Cc: Andrew Morton Cc: Yinghai Lu Cc: "Eric W. Biederman" --- drivers/usb/early/ehci-dbgp.c | 45 +++++++++++++++++++++++----------------- 1 files changed, 26 insertions(+), 19 deletions(-) diff --git a/drivers/usb/early/ehci-dbgp.c b/drivers/usb/early/ehci-dbgp.c index f4bfe31..6198ebd 100644 --- a/drivers/usb/early/ehci-dbgp.c +++ b/drivers/usb/early/ehci-dbgp.c @@ -9,6 +9,12 @@ #include #include +#ifdef DBGP_DEBUG +# define dbgp_printk printk +#else +static inline void dbgp_printk(const char *fmt, ...) { } +#endif + static struct ehci_caps __iomem *ehci_caps; static struct ehci_regs __iomem *ehci_regs; static struct ehci_dbg_port __iomem *ehci_debug; @@ -342,6 +348,7 @@ static int __init ehci_reset_port(int port) u32 delay_time, delay; int loop; + dbgp_printk("ehci_reset_port %i\n", port); /* Reset the usb debug port */ portsc = readl(&ehci_regs->port_status[port - 1]); portsc &= ~PORT_PE; @@ -352,14 +359,17 @@ static int __init ehci_reset_port(int port) for (delay_time = 0; delay_time < HUB_RESET_TIMEOUT; delay_time += delay) { dbgp_mdelay(delay); - portsc = readl(&ehci_regs->port_status[port - 1]); + if (!(portsc & PORT_RESET)) + break; + } if (portsc & PORT_RESET) { /* force reset to complete */ - loop = 2; + loop = 100 * 1000; writel(portsc & ~(PORT_RWC_BITS | PORT_RESET), &ehci_regs->port_status[port - 1]); do { + udelay(1); portsc = readl(&ehci_regs->port_status[port-1]); } while ((portsc & PORT_RESET) && (--loop > 0)); } @@ -375,7 +385,6 @@ static int __init ehci_reset_port(int port) /* If we've finished resetting, then break out of the loop */ if (!(portsc & PORT_RESET) && (portsc & PORT_PE)) return 0; - } return -EBUSY; } @@ -384,24 +393,18 @@ static int __init ehci_wait_for_port(int port) u32 status; int ret, reps; - for (reps = 0; reps < 3; reps++) { - dbgp_mdelay(100); + for (reps = 0; reps < 300; reps++) { status = readl(&ehci_regs->status); - if (status & STS_PCD) { - ret = ehci_reset_port(port); - if (ret == 0) - return 0; - } + if (status & STS_PCD) + break; + dbgp_mdelay(1); } + ret = ehci_reset_port(port); + if (ret == 0) + return 0; return -ENOTCONN; } -#ifdef DBGP_DEBUG -# define dbgp_printk early_printk -#else -static inline void dbgp_printk(const char *fmt, ...) { } -#endif - typedef void (*set_debug_port_t)(int port); static void __init default_set_debug_port(int port) @@ -520,7 +523,7 @@ try_next_port: return -1; } - loop = 10; + loop = 250 * 1000; /* Reset the EHCI controller */ cmd = readl(&ehci_regs->command); cmd |= CMD_RESET; @@ -540,6 +543,7 @@ try_next_port: ctrl |= DBGP_OWNER; ctrl &= ~(DBGP_ENABLED | DBGP_INUSE); writel(ctrl, &ehci_debug->control); + udelay(1); /* Start the ehci running */ cmd = readl(&ehci_regs->command); @@ -554,10 +558,13 @@ try_next_port: loop = 10; do { status = readl(&ehci_regs->status); - } while ((status & STS_HALT) && (--loop > 0)); + if (!(status & STS_HALT)) + break; + udelay(1); + } while (--loop > 0); if (!loop) { - dbgp_printk("ehci can be started\n"); + dbgp_printk("ehci can not be started\n"); return -1; } dbgp_printk("ehci started\n"); -- 1.6.0.3.523.g304d0 -- 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/