From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 AB22B18E2A; Fri, 27 Sep 2024 01:02:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727398922; cv=none; b=GNMJxI7Srzm4IbSae08vP093IbfftpGWb0i3D+VlCzWxgQdZ/nmISCcnV1Nlay+CFtQfGBFUqEgQI7ryzfEA6ol34MeBNyfV/wxnaT9LCHA7LC1d7U1Y8vWjbmSTU/cMZOIAM7ClkjtneaDs2U0dJhyCMTdNGwABeQ4lxMxWVuQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727398922; c=relaxed/simple; bh=QwFqsHNlpuuvWKjYk0EGwhOqVlEYCspxRg9api5E/vE=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=XSzZvagG6KXOybN4rc+X3ZaSXZ31tqKoUWCL8tAPtHPmFpRDridgMyOTYb2L6gLSsNYYZ52FjxgQZjvyEYZf6VDFBu2zRvwJ1pKr/NNrSjpcXYr62e/8shpcJ68kf5CV2xUE7dY1Q+33/Bxhke1UEjl5Wj7pXi3vlklpCFcTqZc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=tYIlcArb; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="tYIlcArb" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E19F6C4CEC5; Fri, 27 Sep 2024 01:02:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1727398922; bh=QwFqsHNlpuuvWKjYk0EGwhOqVlEYCspxRg9api5E/vE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=tYIlcArbKedHSz8YULbnzx9fiF/+y1D8KW8Sr4L/tn+xJBVd+Yw+2TFNQN7BYG+lv 2mLEkX7URktppKUeQZj91I5gpHiQyzZ5jIv2/7y4Sh4jNGu1aMJGeMWm1wXY2ch7oY /cq0gIY+vou5pJBMgPFs/k5T8R0u202jSMyVdf4+/48s/XEwGVhQlj753h7BJ3Qt1T wwZqobY066taEEdQ5yHePn2kX9kyLzB/Xvq7wHIw08C1HI8oMh3n+hEyeJ36ROsC/L FASOeMG/6A/FV3AQjExf9IK7jxrSMk+ryP3C0dgT9IVrO5APCo6W1r7NuM4prXoZ6G WS/aBXS34f8aw== Date: Fri, 27 Sep 2024 09:01:53 +0800 From: Peter Chen To: Xu Yang Cc: gregkh@linuxfoundation.org, linux-usb@vger.kernel.org, imx@lists.linux.dev, jun.li@nxp.com Subject: Re: [PATCH v3 2/3] usb: chipidea: udc: improve dTD link logic Message-ID: <20240927010153.GA438662@nchen-desktop> References: <20240926022906.473319-1-xu.yang_2@nxp.com> <20240926022906.473319-2-xu.yang_2@nxp.com> Precedence: bulk X-Mailing-List: linux-usb@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240926022906.473319-2-xu.yang_2@nxp.com> On 24-09-26 10:29:05, Xu Yang wrote: > Currently, ATDTW semaphore is used to safety link new dTD to dQH. But this > code has a bug when the endpoint is already in error before polling ATDTW > or just met error during polling ATDTW. In that cases, ATDTW will never > turn to 1 and the cpu will busy loop there. > > When the endpoint met error, ENDPTSTAT will be cleared by HW. Therefore, > ENDPTSTAT should also be considered during this process. In case of > endpoint error, the current dTD should not be pushed to the head of dQH > since some dTDs may be still not executed. Therefore, the link logic is > also improved accordingly. > > Signed-off-by: Xu Yang Acked-by: Peter Chen > > --- > Changes in v2: > - modify comments > - fix kernel test robot build warning by using cpu_to_le32 > - add fix tag and cc stable > Changes in v3: > - remove fixes tag and stable maillist > --- > drivers/usb/chipidea/udc.c | 9 ++++++++- > 1 file changed, 8 insertions(+), 1 deletion(-) > > diff --git a/drivers/usb/chipidea/udc.c b/drivers/usb/chipidea/udc.c > index b9ccf62e0a50..0132bb25c9b5 100644 > --- a/drivers/usb/chipidea/udc.c > +++ b/drivers/usb/chipidea/udc.c > @@ -612,10 +612,17 @@ static int _hardware_enqueue(struct ci_hw_ep *hwep, struct ci_hw_req *hwreq) > do { > hw_write(ci, OP_USBCMD, USBCMD_ATDTW, USBCMD_ATDTW); > tmp_stat = hw_read(ci, OP_ENDPTSTAT, BIT(n)); > - } while (!hw_read(ci, OP_USBCMD, USBCMD_ATDTW)); > + } while (!hw_read(ci, OP_USBCMD, USBCMD_ATDTW) && tmp_stat); > hw_write(ci, OP_USBCMD, USBCMD_ATDTW, 0); > if (tmp_stat) > goto done; > + > + /* OP_ENDPTSTAT will be clear by HW when the endpoint met > + * err. This dTD don't push to dQH if current dTD point is > + * not the last one in previous request. > + */ > + if (hwep->qh.ptr->curr != cpu_to_le32(prevlastnode->dma)) > + goto done; > } > > /* QH configuration */ > -- > 2.34.1 >