From mboxrd@z Thu Jan 1 00:00:00 1970 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=-15.3 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 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 AEB16C433DB for ; Fri, 5 Mar 2021 15:35:38 +0000 (UTC) Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 321516508D for ; Fri, 5 Mar 2021 15:35:38 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 321516508D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=rowland.harvard.edu Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=desiato.20200630; h=Sender:Content-Transfer-Encoding :Content-Type:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References:Message-ID: Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=PEbRb6NuT3jGfBooUXoHdjZnbtJn5ia+cysMF/XBm+w=; b=G0F/f9tHL76YiALzAhbyX9wZI eWh9GeshHFv0xSbKIvUvXLMAgpuc4cW+pX1J+X366w4kU9OoR0X0ZOOf7ww5ydOmTYVyeICxCvBqu pWFa38PKzGPpZgXF+tifCoQDGcpCpBZAylsKmG3J/tPq8K3FSzcA+We1fVxPpj8J0mRjAxnf6fSDz S9UvPxgJ+/rUmjwASJsqjO8R99VTbE/Ncn/jTD1yGQF5tAscVgG2ugYQMfK8hJrXtvd8qeUz60rNi zZKFvDhq5RqzxPBYL6LW0x9lP74Pju7GAwr3HDdyRF62OExB3D8V/MQDdEx5+QWosGllbfIA1K60h HVW7bzhRA==; Received: from localhost ([::1] helo=desiato.infradead.org) by desiato.infradead.org with esmtp (Exim 4.94 #2 (Red Hat Linux)) id 1lICSO-00FSmY-8z; Fri, 05 Mar 2021 15:33:36 +0000 Received: from netrider.rowland.org ([192.131.102.5]) by desiato.infradead.org with smtp (Exim 4.94 #2 (Red Hat Linux)) id 1lICS3-00FSjT-Sa for linux-arm-kernel@lists.infradead.org; Fri, 05 Mar 2021 15:33:18 +0000 Received: (qmail 39139 invoked by uid 1000); 5 Mar 2021 10:33:12 -0500 Date: Fri, 5 Mar 2021 10:33:12 -0500 From: Alan Stern To: Chunfeng Yun Cc: Mathias Nyman , Greg Kroah-Hartman , Ikjoon Jang , Matthias Brugger , linux-usb@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, linux-kernel@vger.kernel.org, Nicolas Boichat , Eddie Hung Subject: Re: [PATCH 16/17] usb: common: add function to get interval expressed in us unit Message-ID: <20210305153312.GA38200@rowland.harvard.edu> References: <1614934975-15188-1-git-send-email-chunfeng.yun@mediatek.com> <1614934975-15188-16-git-send-email-chunfeng.yun@mediatek.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1614934975-15188-16-git-send-email-chunfeng.yun@mediatek.com> User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210305_153316_840963_49D496C3 X-CRM114-Status: GOOD ( 16.99 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Fri, Mar 05, 2021 at 05:02:54PM +0800, Chunfeng Yun wrote: > Add a new function to convert bInterval into the time expressed > in 1us unit. > > Signed-off-by: Chunfeng Yun > --- > --- a/drivers/usb/common/common.c > +++ b/drivers/usb/common/common.c > @@ -165,6 +165,39 @@ enum usb_dr_mode usb_get_dr_mode(struct device *dev) > } > EXPORT_SYMBOL_GPL(usb_get_dr_mode); > > +unsigned int usb_decode_interval(const struct usb_endpoint_descriptor *epd, > + enum usb_device_speed speed) > +{ > + unsigned int interval = 0; > + > + switch (usb_endpoint_type(epd)) { > + case USB_ENDPOINT_XFER_CONTROL: > + /* uframes per NAK */ > + if (speed == USB_SPEED_HIGH) > + interval = epd->bInterval; > + break; > + case USB_ENDPOINT_XFER_ISOC: > + interval = 1 << (epd->bInterval - 1); > + break; > + case USB_ENDPOINT_XFER_BULK: > + /* uframes per NAK */ > + if (speed == USB_SPEED_HIGH && usb_endpoint_dir_out(epd)) > + interval = epd->bInterval; > + break; > + case USB_ENDPOINT_XFER_INT: > + if (speed >= USB_SPEED_HIGH) > + interval = 1 << (epd->bInterval - 1); > + else > + interval = epd->bInterval; > + break; > + } > + > + interval *= (speed >= USB_SPEED_HIGH) ? 125 : 1000; > + > + return interval; > +} > +EXPORT_SYMBOL_GPL(usb_decode_interval); > --- a/include/linux/usb/ch9.h > +++ b/include/linux/usb/ch9.h > @@ -90,6 +90,17 @@ extern enum usb_ssp_rate usb_get_maximum_ssp_rate(struct device *dev); > */ > extern const char *usb_state_string(enum usb_device_state state); > > +/** > + * usb_decode_interval - Decode bInterval into the time expressed in 1us unit > + * @epd: The descriptor of the endpoint > + * @speed: The speed that the endpoint works as > + * > + * Function returns the interval expressed in 1us unit for servicing > + * endpoint for data transfers. > + */ > +unsigned int usb_decode_interval(const struct usb_endpoint_descriptor *epd, > + enum usb_device_speed speed); As a general rule, I believe people expect to find the kerneldoc for a function next to the function's definition, not next to the declaration in a header file. Alan Stern _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel