From patchwork Mon May 5 12:56:30 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Mathias Nyman X-Patchwork-Id: 889048 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.16]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id EEBA2146D53; Mon, 5 May 2025 12:57:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.16 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746449846; cv=none; b=Y/3gAFfxGw9U9I+21USVMQjRnZybl6+KRG5WO9W2p0a8sWnOcaCBBJod7ZZMcJ2ffvPwFJ3JHjc9dVoScTvCjdJxI77y54Ii0GVIZG6fWDEjoHnhgTmFmVIOCx9ztiyEKaft/VlrJtiuc14EerGYG0c7wKb10O8mBK8cCT/icoU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746449846; c=relaxed/simple; bh=A8dahzrlKe2KglU8LHZBXCxvVFCHODOywH9O+yQASNU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=H4hH1R6Y3sqPELpNi+SlNxitt1ahBAi8MEdIacJOIgapDrcabNzr5GDxbkAZKMcPMse4JCSsjQbPDrxIxXlCW3Du2JnOI/sYBQJRQ0EHNRwNmhUOSgmNTMF/I0ys19B0vrLVaPVZwmiFKfRkr+gpj+YSyHk46PDV6le1WhU+9rI= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=none smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=exql5B09; arc=none smtp.client-ip=192.198.163.16 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="exql5B09" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1746449845; x=1777985845; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=A8dahzrlKe2KglU8LHZBXCxvVFCHODOywH9O+yQASNU=; b=exql5B09DKgDbYEO84PPTSArqOsnlI2KNBIEr60zFntrZjTRi7poc4iw qUdeZhP4BlrZv9JY9fUHfeUvI8UZf6se1wzhHmnWvYR1RvAOUVpPyiegR ZZ724rCyM95mJqOLMZUX/2XTFtkyhvQKpoYYrek5dVJUrOIu1FHloId6S cLklhRYr9mR1Z2UJX+8DRm4vVfilJtGscyncaW9FJnAjeHJf+S2K6DzhZ RGe6NqqMbc2p28/njWVn+dyPjmzFlpZUhiA+v0E5S2CNBAqrXHqPIoJ80 JctBam0ind0+DhcT8t6HNNPF4Sc7o/Qad6Zur5gVmKI6LgytACGbBhyPL A==; X-CSE-ConnectionGUID: lEO8AYKXQoa6IFcaYLCanw== X-CSE-MsgGUID: TGeL6MqUSVWnOf1Husiy+g== X-IronPort-AV: E=McAfee;i="6700,10204,11423"; a="35675911" X-IronPort-AV: E=Sophos;i="6.15,262,1739865600"; d="scan'208";a="35675911" Received: from orviesa010.jf.intel.com ([10.64.159.150]) by fmvoesa110.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 May 2025 05:57:24 -0700 X-CSE-ConnectionGUID: DsmJJm4wS9WNyh+Wwzc69A== X-CSE-MsgGUID: ileZhGtrSdSkoxzhti2K6g== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.15,262,1739865600"; d="scan'208";a="135151089" Received: from unknown (HELO mnyman-desk.fi.intel.com) ([10.237.72.199]) by orviesa010.jf.intel.com with ESMTP; 05 May 2025 05:57:22 -0700 From: Mathias Nyman To: Cc: , Mathias Nyman , =?utf-8?q?=C5=81ukasz_Bartos?= =?utf-8?q?ik?= , stable@vger.kernel.org Subject: [PATCH 2/2] xhci: dbc: Avoid event polling busyloop if pending rx transfers are inactive. Date: Mon, 5 May 2025 15:56:30 +0300 Message-ID: <20250505125630.561699-3-mathias.nyman@linux.intel.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20250505125630.561699-1-mathias.nyman@linux.intel.com> References: <20250505125630.561699-1-mathias.nyman@linux.intel.com> Precedence: bulk X-Mailing-List: linux-usb@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Event polling delay is set to 0 if there are any pending requests in either rx or tx requests lists. Checking for pending requests does not work well for "IN" transfers as the tty driver always queues requests to the list and TRBs to the ring, preparing to receive data from the host. This causes unnecessary busylooping and cpu hogging. Only set the event polling delay to 0 if there are pending tx "write" transfers, or if it was less than 10ms since last active data transfer in any direction. Cc: Łukasz Bartosik Fixes: fb18e5bb9660 ("xhci: dbc: poll at different rate depending on data transfer activity") Cc: stable@vger.kernel.org Signed-off-by: Mathias Nyman --- drivers/usb/host/xhci-dbgcap.c | 19 ++++++++++++++++--- drivers/usb/host/xhci-dbgcap.h | 3 +++ 2 files changed, 19 insertions(+), 3 deletions(-) diff --git a/drivers/usb/host/xhci-dbgcap.c b/drivers/usb/host/xhci-dbgcap.c index fd7895b24367..0d4ce5734165 100644 --- a/drivers/usb/host/xhci-dbgcap.c +++ b/drivers/usb/host/xhci-dbgcap.c @@ -823,6 +823,7 @@ static enum evtreturn xhci_dbc_do_handle_events(struct xhci_dbc *dbc) { dma_addr_t deq; union xhci_trb *evt; + enum evtreturn ret = EVT_DONE; u32 ctrl, portsc; bool update_erdp = false; @@ -909,6 +910,7 @@ static enum evtreturn xhci_dbc_do_handle_events(struct xhci_dbc *dbc) break; case TRB_TYPE(TRB_TRANSFER): dbc_handle_xfer_event(dbc, evt); + ret = EVT_XFER_DONE; break; default: break; @@ -927,7 +929,7 @@ static enum evtreturn xhci_dbc_do_handle_events(struct xhci_dbc *dbc) lo_hi_writeq(deq, &dbc->regs->erdp); } - return EVT_DONE; + return ret; } static void xhci_dbc_handle_events(struct work_struct *work) @@ -936,6 +938,7 @@ static void xhci_dbc_handle_events(struct work_struct *work) struct xhci_dbc *dbc; unsigned long flags; unsigned int poll_interval; + unsigned long busypoll_timelimit; dbc = container_of(to_delayed_work(work), struct xhci_dbc, event_work); poll_interval = dbc->poll_interval; @@ -954,11 +957,21 @@ static void xhci_dbc_handle_events(struct work_struct *work) dbc->driver->disconnect(dbc); break; case EVT_DONE: - /* set fast poll rate if there are pending data transfers */ + /* + * Set fast poll rate if there are pending out transfers, or + * a transfer was recently processed + */ + busypoll_timelimit = dbc->xfer_timestamp + + msecs_to_jiffies(DBC_XFER_INACTIVITY_TIMEOUT); + if (!list_empty(&dbc->eps[BULK_OUT].list_pending) || - !list_empty(&dbc->eps[BULK_IN].list_pending)) + time_is_after_jiffies(busypoll_timelimit)) poll_interval = 0; break; + case EVT_XFER_DONE: + dbc->xfer_timestamp = jiffies; + poll_interval = 0; + break; default: dev_info(dbc->dev, "stop handling dbc events\n"); return; diff --git a/drivers/usb/host/xhci-dbgcap.h b/drivers/usb/host/xhci-dbgcap.h index 9dc8f4d8077c..47ac72c2286d 100644 --- a/drivers/usb/host/xhci-dbgcap.h +++ b/drivers/usb/host/xhci-dbgcap.h @@ -96,6 +96,7 @@ struct dbc_ep { #define DBC_WRITE_BUF_SIZE 8192 #define DBC_POLL_INTERVAL_DEFAULT 64 /* milliseconds */ #define DBC_POLL_INTERVAL_MAX 5000 /* milliseconds */ +#define DBC_XFER_INACTIVITY_TIMEOUT 10 /* milliseconds */ /* * Private structure for DbC hardware state: */ @@ -142,6 +143,7 @@ struct xhci_dbc { enum dbc_state state; struct delayed_work event_work; unsigned int poll_interval; /* ms */ + unsigned long xfer_timestamp; unsigned resume_required:1; struct dbc_ep eps[2]; @@ -187,6 +189,7 @@ struct dbc_request { enum evtreturn { EVT_ERR = -1, EVT_DONE, + EVT_XFER_DONE, EVT_GSER, EVT_DISC, };