From patchwork Mon May 17 23:36:09 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Badhri Jagan Sridharan X-Patchwork-Id: 12263363 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-26.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT,USER_IN_DEF_DKIM_WL autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 79A10C433B4 for ; Mon, 17 May 2021 23:36:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 59DFF61285 for ; Mon, 17 May 2021 23:36:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344486AbhEQXhd (ORCPT ); Mon, 17 May 2021 19:37:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51260 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344478AbhEQXhc (ORCPT ); Mon, 17 May 2021 19:37:32 -0400 Received: from mail-yb1-xb49.google.com (mail-yb1-xb49.google.com [IPv6:2607:f8b0:4864:20::b49]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 35F3AC061573 for ; Mon, 17 May 2021 16:36:15 -0700 (PDT) Received: by mail-yb1-xb49.google.com with SMTP id v184-20020a257ac10000b02904f84a5c5297so11357841ybc.16 for ; Mon, 17 May 2021 16:36:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=q+UoCkDGAvRqrLzMap85aK4sT0upthVT2kMDgBIV4RE=; b=nIvh1nvCynlMWsxrbrXssOnrwQgJaKqZul6qCGlZdEtCR8uM6Yjzba0iP1xUxLL+U3 QeueNVoJ06ITkT+tmp4WdOgxMTgnagYMyUWIA71EfaO4pK4hU207CThEwDUgHV0R+7lE 9iuSXWaa6Qt42o2oAjWttoN75vrpJvcbbdL7loOrw9gTxZw6WOawf+j8k1a5OHi8jYKy tmDhO5r8ooCRVSh4ylTyemWoQZTU/PMqEimGVBDDOgY9bKo+aSsp9le+QXa8tprQ/mWN dn5yziEzBxNFa2sPiL2S56W+FAqIRuAN0Z7p/NEwenHaVzdf3NgftJhI10EfAnChhpqg QVyA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=q+UoCkDGAvRqrLzMap85aK4sT0upthVT2kMDgBIV4RE=; b=iuB0gHiMn+T0L/YJNTG0HTlqWWy25kXJktstHlgtvnI0J7lzNNbVGV1ZwxzRlpXzfQ ysKXS8u1f0UIV3yYfVGa7vMdCykZcIjVgrstul8VNsnFdheU31A1Ztcj1VNoaSu925dw 72qNWLyeX+3k0HVpkVdp9q3+YpY90o3Ygzp78U6Yz18saBWzwWz1RaKzjZrvoQUgvxm6 A9Fc6NtA+gZBwwgwsmZVFhXD2zkgmfDAuR81yeLcyQGzhZDWEwtfhtXqDMg08q4pv8UE PUG2TQ/2Yxww8vZrUGdypqvVeEowTCGE5SU8FgQ+2xhroRqjmDIFLLredXywEajRRpyg ZJLg== X-Gm-Message-State: AOAM531reroaVSt9jwVmif+U7+cCBGkVwS/p6+5lQIewLW1/jMEwy939 CFGFEqCiBlJkv7dOoosiyr4WQtVVPEI= X-Google-Smtp-Source: ABdhPJxyNIDZXlnARe5+IXunIQ1I+2VXbPVtN+U7UXk5wbWO8hIpBuQ1bL6dgPJrMYPRnrTTXmV7IAIjv/o= X-Received: from badhri.mtv.corp.google.com ([2620:15c:211:201:b562:7011:fe35:1c9e]) (user=badhri job=sendgmr) by 2002:a25:2f57:: with SMTP id v84mr3257285ybv.107.1621294574479; Mon, 17 May 2021 16:36:14 -0700 (PDT) Date: Mon, 17 May 2021 16:36:09 -0700 In-Reply-To: <20210517233609.610248-1-badhri@google.com> Message-Id: <20210517233609.610248-2-badhri@google.com> Mime-Version: 1.0 References: <20210517233609.610248-1-badhri@google.com> X-Mailer: git-send-email 2.31.1.751.gd2f1c929bd-goog Subject: [PATCH v1 2/2] usb: typec: tcpm: Add module parameter to wrap around logs From: Badhri Jagan Sridharan To: Guenter Roeck , Heikki Krogerus , Greg Kroah-Hartman Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, Kyle Tso , Badhri Jagan Sridharan Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org When the buffer is full, TCPM stops logging into the buffer. This change adds log_wraparound module parameter which when set flushes out the oldest log entries (FIFO) to make way for the newer ones. Signed-off-by: Badhri Jagan Sridharan --- drivers/usb/typec/tcpm/tcpm.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c index b79194919b27..a369decade60 100644 --- a/drivers/usb/typec/tcpm/tcpm.c +++ b/drivers/usb/typec/tcpm/tcpm.c @@ -38,6 +38,10 @@ static bool modparam_log_misc_dev; module_param_named(log_misc_dev, modparam_log_misc_dev, bool, 0444); MODULE_PARM_DESC(log_misc_dev, "Expose tcpm logs through misc device"); +static bool modparam_log_wraparound; +module_param_named(log_wraparound, modparam_log_wraparound, bool, 0444); +MODULE_PARM_DESC(log_wraparound, "Wrap around logs"); + #define FOREACH_STATE(S) \ S(INVALID_STATE), \ S(TOGGLING), \ @@ -597,7 +601,7 @@ static void _tcpm_log(struct tcpm_port *port, const char *fmt, va_list args) vsnprintf(tmpbuffer, sizeof(tmpbuffer), fmt, args); - if (tcpm_log_full(port)) { + if (!modparam_log_wraparound && tcpm_log_full(port)) { port->logbuffer_head = max(port->logbuffer_head - 1, 0); strcpy(tmpbuffer, "overflow"); } @@ -621,6 +625,9 @@ static void _tcpm_log(struct tcpm_port *port, const char *fmt, va_list args) (unsigned long)ts_nsec, rem_nsec / 1000, tmpbuffer); port->logbuffer_head = (port->logbuffer_head + 1) % LOG_BUFFER_ENTRIES; + if (modparam_log_wraparound && port->logbuffer_head == port->logbuffer_tail) + port->logbuffer_tail = + (port->logbuffer_tail + 1) % LOG_BUFFER_ENTRIES; abort: mutex_unlock(&port->logbuffer_lock); @@ -733,7 +740,7 @@ static int tcpm_log_show(struct seq_file *s, void *v) seq_printf(s, "%s\n", port->logbuffer[tail]); tail = (tail + 1) % LOG_BUFFER_ENTRIES; } - if (!seq_has_overflowed(s)) + if (!modparam_log_wraparound && !seq_has_overflowed(s)) port->logbuffer_tail = tail; mutex_unlock(&port->logbuffer_lock);