From patchwork Fri Jun 4 08:05:36 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tony Lindgren X-Patchwork-Id: 454505 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable 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 F1BB8C4708F for ; Fri, 4 Jun 2021 08:05:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DB39261422 for ; Fri, 4 Jun 2021 08:05:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230080AbhFDIHd (ORCPT ); Fri, 4 Jun 2021 04:07:33 -0400 Received: from muru.com ([72.249.23.125]:36196 "EHLO muru.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229921AbhFDIHd (ORCPT ); Fri, 4 Jun 2021 04:07:33 -0400 Received: from hillo.muru.com (localhost [127.0.0.1]) by muru.com (Postfix) with ESMTP id 0490081A8; Fri, 4 Jun 2021 08:05:53 +0000 (UTC) From: Tony Lindgren To: Bin Liu , Greg Kroah-Hartman Cc: linux-usb@vger.kernel.org, linux-omap@vger.kernel.org, Alexandre Belloni , Andreas Kemnade , Bhushan Shah , Drew Fustini , Thomas Petazzoni Subject: [PATCH 2/2] usb: musb: Implement tracing for state change events Date: Fri, 4 Jun 2021 11:05:36 +0300 Message-Id: <20210604080536.12185-2-tony@atomide.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210604080536.12185-1-tony@atomide.com> References: <20210604080536.12185-1-tony@atomide.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org The devctl register on musb is the only way to get state information on musb. The hardware can easily get confused because it tries to do things on it's own automagically, and things like slow VBUS rise can make things fail. Let's make it easier to debug the ongoing state change issues that keep popping up on regular basis and add tracing support. With these changes we can easily trace musb state change events with: echo 1 > /sys/kernel/debug/tracing/events/musb/musb_state/enable cat /sys/kernel/debug/tracing/trace_pipe echo 0 > /sys/kernel/debug/tracing/events/musb/musb_state/enable Cc: Alexandre Belloni Cc: Andreas Kemnade Cc: Bhushan Shah Cc: Drew Fustini Cc: Thomas Petazzoni Signed-off-by: Tony Lindgren --- drivers/usb/musb/musb_core.c | 34 ++++++++++++++++++---------------- drivers/usb/musb/musb_trace.h | 17 +++++++++++++++++ 2 files changed, 35 insertions(+), 16 deletions(-) diff --git a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c --- a/drivers/usb/musb/musb_core.c +++ b/drivers/usb/musb/musb_core.c @@ -480,9 +480,7 @@ int musb_set_host(struct musb *musb) devctl = musb_read_devctl(musb); if (!(devctl & MUSB_DEVCTL_BDEVICE)) { - dev_info(musb->controller, - "%s: already in host mode: %02x\n", - __func__, devctl); + trace_musb_state(musb, devctl, "Already in host mode"); goto init_data; } @@ -499,6 +497,9 @@ int musb_set_host(struct musb *musb) return error; } + devctl = musb_read_devctl(musb); + trace_musb_state(musb, devctl, "Host mode set"); + init_data: musb->is_active = 1; musb->xceiv->otg->state = OTG_STATE_A_IDLE; @@ -526,10 +527,7 @@ int musb_set_peripheral(struct musb *musb) devctl = musb_read_devctl(musb); if (devctl & MUSB_DEVCTL_BDEVICE) { - dev_info(musb->controller, - "%s: already in peripheral mode: %02x\n", - __func__, devctl); - + trace_musb_state(musb, devctl, "Already in peripheral mode"); goto init_data; } @@ -546,6 +544,9 @@ int musb_set_peripheral(struct musb *musb) return error; } + devctl = musb_read_devctl(musb); + trace_musb_state(musb, devctl, "Peripheral mode set"); + init_data: musb->is_active = 0; musb->xceiv->otg->state = OTG_STATE_B_IDLE; @@ -1984,10 +1985,11 @@ ATTRIBUTE_GROUPS(musb); #define MUSB_QUIRK_A_DISCONNECT_19 ((3 << MUSB_DEVCTL_VBUS_SHIFT) | \ MUSB_DEVCTL_SESSION) -static bool musb_state_needs_recheck(struct musb *musb, const char *desc) +static bool musb_state_needs_recheck(struct musb *musb, u8 devctl, + const char *desc) { if (musb->quirk_retries && !musb->flush_irq_work) { - musb_dbg(musb, desc); + trace_musb_state(musb, devctl, desc); schedule_delayed_work(&musb->irq_work, msecs_to_jiffies(1000)); musb->quirk_retries--; @@ -2018,21 +2020,21 @@ static void musb_pm_runtime_check_session(struct musb *musb) MUSB_DEVCTL_HR; switch (devctl & ~s) { case MUSB_QUIRK_B_DISCONNECT_99: - musb_state_needs_recheck(musb, - "Poll devctl in case of suspend after disconnect\n"); + musb_state_needs_recheck(musb, devctl, + "Poll devctl in case of suspend after disconnect"); break; case MUSB_QUIRK_B_INVALID_VBUS_91: - if (musb_state_needs_recheck(musb, + if (musb_state_needs_recheck(musb, devctl, "Poll devctl on invalid vbus, assume no session")) return; fallthrough; case MUSB_QUIRK_A_DISCONNECT_19: - if (musb_state_needs_recheck(musb, + if (musb_state_needs_recheck(musb, devctl, "Poll devctl on possible host mode disconnect")) return; if (!musb->session) break; - musb_dbg(musb, "Allow PM on possible host mode disconnect"); + trace_musb_state(musb, devctl, "Allow PM on possible host mode disconnect"); pm_runtime_mark_last_busy(musb->controller); pm_runtime_put_autosuspend(musb->controller); musb->session = false; @@ -2048,7 +2050,7 @@ static void musb_pm_runtime_check_session(struct musb *musb) /* Block PM or allow PM? */ if (s) { - musb_dbg(musb, "Block PM on active session: %02x", devctl); + trace_musb_state(musb, devctl, "Block PM on active session"); error = pm_runtime_get_sync(musb->controller); if (error < 0) dev_err(musb->controller, "Could not enable: %i\n", @@ -2064,7 +2066,7 @@ static void musb_pm_runtime_check_session(struct musb *musb) schedule_delayed_work(&musb->irq_work, msecs_to_jiffies(3000)); } else { - musb_dbg(musb, "Allow PM with no session: %02x", devctl); + trace_musb_state(musb, devctl, "Allow PM with no session"); pm_runtime_mark_last_busy(musb->controller); pm_runtime_put_autosuspend(musb->controller); } diff --git a/drivers/usb/musb/musb_trace.h b/drivers/usb/musb/musb_trace.h --- a/drivers/usb/musb/musb_trace.h +++ b/drivers/usb/musb/musb_trace.h @@ -37,6 +37,23 @@ TRACE_EVENT(musb_log, TP_printk("%s: %s", __get_str(name), __get_str(msg)) ); +TRACE_EVENT(musb_state, + TP_PROTO(struct musb *musb, u8 devctl, const char *desc), + TP_ARGS(musb, devctl, desc), + TP_STRUCT__entry( + __string(name, dev_name(musb->controller)) + __field(u8, devctl) + __string(desc, desc) + ), + TP_fast_assign( + __assign_str(name, dev_name(musb->controller)); + __entry->devctl = devctl; + __assign_str(desc, desc); + ), + TP_printk("%s: devctl: %02x %s", __get_str(name), __entry->devctl, + __get_str(desc)) +); + DECLARE_EVENT_CLASS(musb_regb, TP_PROTO(void *caller, const void __iomem *addr, unsigned int offset, u8 data),