From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933799AbcAZEPb (ORCPT ); Mon, 25 Jan 2016 23:15:31 -0500 Received: from mga02.intel.com ([134.134.136.20]:41995 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933588AbcAZEPP (ORCPT ); Mon, 25 Jan 2016 23:15:15 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.22,348,1449561600"; d="scan'208";a="36179297" From: Lu Baolu To: Greg Kroah-Hartman Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, Lu Baolu Subject: [PATCH v6 05/12] usb: dbc: add debug buffer Date: Tue, 26 Jan 2016 12:14:18 +0800 Message-Id: <1453781665-4714-6-git-send-email-baolu.lu@linux.intel.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1453781665-4714-1-git-send-email-baolu.lu@linux.intel.com> References: <1453781665-4714-1-git-send-email-baolu.lu@linux.intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org "printk" is not suitable for dbc debugging especially when console is in usage. This patch adds a debug buffer in dbc driver and puts the debug messages in this local buffer. The debug buffer could be dumped whenever the console is not in use. This part of code will not be visible unless DBC_DEBUG is defined. Signed-off-by: Lu Baolu --- drivers/usb/early/xhci-dbc.c | 62 ++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 60 insertions(+), 2 deletions(-) diff --git a/drivers/usb/early/xhci-dbc.c b/drivers/usb/early/xhci-dbc.c index 41ce116..6855048 100644 --- a/drivers/usb/early/xhci-dbc.c +++ b/drivers/usb/early/xhci-dbc.c @@ -32,8 +32,64 @@ static struct xdbc_state xdbc_stat; static struct xdbc_state *xdbcp = &xdbc_stat; #ifdef DBC_DEBUG -/* place holder */ -#define xdbc_trace printk +#define XDBC_DEBUG_BUF_SIZE (PAGE_SIZE * 32) +#define MSG_MAX_LINE 128 +static char xdbc_debug_buf[XDBC_DEBUG_BUF_SIZE]; +static void xdbc_trace(const char *fmt, ...) +{ + int i, size; + va_list args; + static int pos; + char temp_buf[MSG_MAX_LINE]; + + if (pos >= XDBC_DEBUG_BUF_SIZE - 1) + return; + + memset(temp_buf, 0, MSG_MAX_LINE); + va_start(args, fmt); + vsnprintf(temp_buf, MSG_MAX_LINE - 1, fmt, args); + va_end(args); + + i = 0; + size = strlen(temp_buf); + while (i < size) { + xdbc_debug_buf[pos] = temp_buf[i]; + pos++; + i++; + + if (pos >= XDBC_DEBUG_BUF_SIZE - 1) + break; + } +} + +static void xdbc_dump_debug_buffer(void) +{ + int index = 0; + int count = 0; + char dump_buf[MSG_MAX_LINE]; + + xdbc_trace("The end of DbC trace buffer\n"); + pr_notice("DBC debug buffer:\n"); + memset(dump_buf, 0, MSG_MAX_LINE); + + while (index < XDBC_DEBUG_BUF_SIZE) { + if (!xdbc_debug_buf[index]) + break; + + if (xdbc_debug_buf[index] == '\n' || + count >= MSG_MAX_LINE - 1) { + pr_notice("DBC: @%08x %s\n", index, dump_buf); + memset(dump_buf, 0, MSG_MAX_LINE); + count = 0; + } else { + dump_buf[count] = xdbc_debug_buf[index]; + count++; + } + + index++; + } +} + static void xdbc_dbg_dump_regs(char *str) { if (!xdbcp->xdbc_reg) { @@ -165,6 +221,7 @@ static void xdbc_dbg_dump_data(char *str) #else static inline void xdbc_trace(const char *fmt, ...) { } +static inline void xdbc_dump_debug_buffer(void) { } static inline void xdbc_dbg_dump_regs(char *str) { } static inline void xdbc_dbg_dump_data(char *str) { } #endif /* DBC_DEBUG */ @@ -819,6 +876,7 @@ int __init early_xdbc_init(char *s) pr_notice("failed to setup xHCI DbC connection\n"); xdbcp->xhci_base = NULL; xdbcp->xdbc_reg = NULL; + xdbc_dump_debug_buffer(); return ret; } -- 2.1.4