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=-16.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 86919C4320A for ; Thu, 26 Aug 2021 11:17:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6C648610A1 for ; Thu, 26 Aug 2021 11:17:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241926AbhHZLSX (ORCPT ); Thu, 26 Aug 2021 07:18:23 -0400 Received: from mail.kernel.org ([198.145.29.99]:57610 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233736AbhHZLSV (ORCPT ); Thu, 26 Aug 2021 07:18:21 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 0A3E3610A4; Thu, 26 Aug 2021 11:17:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1629976654; bh=rj+1dxJfAFKdj8Dhrnrr16eUI58mr8w3p7l4glHVvx0=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=NaMxParJDyi+yixAw+EbULYF6f5FIuXp59gnMDB9xGPA4AqozC6ZkuNhfV1DshSYD ANt4pSy4OgJaw1Pn5ktDc+378vF0A9NGubMsZMolPilYHc0YIQdmNTTw2x20NN4jYG e/N++lLUB5pXl63NzhSON1rfDsLDQnr2VWaPduFw= Date: Thu, 26 Aug 2021 13:17:30 +0200 From: Greg Kroah-Hartman To: Jeaho Hwang Cc: Peter Chen , linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, team-linux@rtst.co.kr, mkbyeon@lselectric.co.kr, khchoib@lselectric.co.kr Subject: Re: [PATCH v2] usb: chipidea: add loop timeout for hw_ep_set_halt() Message-ID: References: <20210817064353.GA669425@ubuntu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210817064353.GA669425@ubuntu> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Aug 17, 2021 at 03:43:53PM +0900, Jeaho Hwang wrote: > If ctrl EP priming is failed (very rare case in standard linux), > hw_ep_set_halt goes infinite loop. waiting 100 times was enough > for zynq7000. > > Signed-off-by: Jeaho Hwang > > diff --git a/drivers/usb/chipidea/udc.c b/drivers/usb/chipidea/udc.c > index 8834ca613721..d73fadb18f32 100644 > --- a/drivers/usb/chipidea/udc.c > +++ b/drivers/usb/chipidea/udc.c > @@ -209,6 +209,9 @@ static int hw_ep_prime(struct ci_hdrc *ci, int num, int dir, int is_ctrl) > return 0; > } > > +/* enough for zynq7000 evaluation board */ > +#define HW_EP_SET_HALT_COUNT_MAX 100 > + > /** > * hw_ep_set_halt: configures ep halt & resets data toggle after clear (execute > * without interruption) > @@ -221,6 +224,7 @@ static int hw_ep_prime(struct ci_hdrc *ci, int num, int dir, int is_ctrl) > */ > static int hw_ep_set_halt(struct ci_hdrc *ci, int num, int dir, int value) > { > + int count = HW_EP_SET_HALT_COUNT_MAX; > if (value != 0 && value != 1) You need a blank line after "int count..." > return -EINVAL; > > @@ -232,9 +236,9 @@ static int hw_ep_set_halt(struct ci_hdrc *ci, int num, int dir, int value) > /* data toggle - reserved for EP0 but it's in ESS */ > hw_write(ci, reg, mask_xs|mask_xr, > value ? mask_xs : mask_xr); > - } while (value != hw_ep_get_halt(ci, num, dir)); > + } while (value != hw_ep_get_halt(ci, num, dir) && --count > 0); > > - return 0; > + return count ? 0 : -EAGAIN; Please spell this out: if (count) return 0; return -EAGAIN; And will the caller properly handle this? thanks, greg k-h