From patchwork Fri Aug 27 05:03:57 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tobias Schramm X-Patchwork-Id: 503605 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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 1F41EC432BE for ; Fri, 27 Aug 2021 05:12:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D75D760187 for ; Fri, 27 Aug 2021 05:12:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230161AbhH0FMu (ORCPT ); Fri, 27 Aug 2021 01:12:50 -0400 Received: from mail.manjaro.org ([116.203.91.91]:58616 "EHLO mail.manjaro.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229645AbhH0FMt (ORCPT ); Fri, 27 Aug 2021 01:12:49 -0400 X-Greylist: delayed 455 seconds by postgrey-1.27 at vger.kernel.org; Fri, 27 Aug 2021 01:12:49 EDT From: Tobias Schramm DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=manjaro.org; s=2021; t=1630040663; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=CCGe3l7vX7fN0xeU/nOfzM7VX7yQ/ff/as6wuEAK9KE=; b=LjpDAzCiCaVwFIh4DfutFmxf9GqvTbwqKiyGitq+ye1tCOhDH8F9LPEGW0zDNbCvM07E9z eyRekW34kHW87+7Nt6LDGMn12tDeIYrVYd81jt9swNaHFBKgA/56hIJ3uiDDO5n0oZ+OIB F4riSGuyThtwOGfIFVKyOgKhA6UHtr3q0ZmjEeOjnZoKYUEnU3F7vK//V6UAwGGDprdv/f gIsukLETAWJNgwTx8rZcJuwCCa2mA7Jhm46pBPvqkeArOvMFmdX+Dib2l/dDm4qbpSwsNl maIlDaZjL2Yejpn1YVV68XA5HsE9hEwIAbOe/2IoyO/rFOBYyIfUbRm1ofFpUA== To: linux-spi@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-rockchip@lists.infradead.org, linux-kernel@vger.kernel.org Cc: Mark Brown , Heiko Stuebner , Tobias Schramm Subject: [PATCH] spi: rockchip: handle zero length transfers without timing out Date: Fri, 27 Aug 2021 07:03:57 +0200 Message-Id: <20210827050357.165409-1-t.schramm@manjaro.org> MIME-Version: 1.0 Authentication-Results: ORIGINATING; auth=pass smtp.auth=t.schramm@manjaro.org smtp.mailfrom=t.schramm@manjaro.org Precedence: bulk List-ID: X-Mailing-List: linux-spi@vger.kernel.org Previously zero length transfers submitted to the Rokchip SPI driver would time out in the SPI layer. This happens because the SPI peripheral does not trigger a transfer completion interrupt for zero length transfers. Fix that by completing zero length transfers immediately at start of transfer. Signed-off-by: Tobias Schramm --- drivers/spi/spi-rockchip.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/spi/spi-rockchip.c b/drivers/spi/spi-rockchip.c index 540861ca2ba3..553b6b9d0222 100644 --- a/drivers/spi/spi-rockchip.c +++ b/drivers/spi/spi-rockchip.c @@ -600,6 +600,12 @@ static int rockchip_spi_transfer_one( int ret; bool use_dma; + /* Zero length transfers won't trigger an interrupt on completion */ + if (!xfer->len) { + spi_finalize_current_transfer(ctlr); + return 1; + } + WARN_ON(readl_relaxed(rs->regs + ROCKCHIP_SPI_SSIENR) && (readl_relaxed(rs->regs + ROCKCHIP_SPI_SR) & SR_BUSY));