From patchwork Thu Dec 4 10:08:44 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andy Yan X-Patchwork-Id: 5441191 Return-Path: X-Original-To: patchwork-dri-devel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 75026BEEA8 for ; Fri, 5 Dec 2014 01:38:46 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id B4AE820211 for ; Fri, 5 Dec 2014 01:38:45 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) by mail.kernel.org (Postfix) with ESMTP id E1A8D20173 for ; Fri, 5 Dec 2014 01:38:44 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id CAAD96E729; Thu, 4 Dec 2014 17:38:31 -0800 (PST) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from lucky1.263xmail.com (lucky1.263xmail.com [211.157.147.131]) by gabe.freedesktop.org (Postfix) with ESMTP id 319416E65A for ; Thu, 4 Dec 2014 02:09:11 -0800 (PST) Received: from andy.yan?rock-chips.com (unknown [192.168.167.128]) by lucky1.263xmail.com (Postfix) with SMTP id B0163104E1; Thu, 4 Dec 2014 18:09:07 +0800 (CST) X-263anti-spam: KSV:0; X-MAIL-GRAY: 1 X-MAIL-DELIVERY: 0 X-KSVirus-check: 0 X-ABS-CHECKED: 4 Received: from localhost.localdomain (localhost.localdomain [127.0.0.1]) by smtp.263.net (Postfix) with ESMTP id BB6961F79C; Thu, 4 Dec 2014 18:09:01 +0800 (CST) X-RL-SENDER: andy.yan@rock-chips.com X-FST-TO: airlied@linux.ie X-SENDER-IP: 127.0.0.1 X-LOGIN-NAME: andy.yan@rock-chips.com X-UNIQUE-TAG: <1d2222367bc24fea187ff53dd5d35208> X-ATTACHMENT-NUM: 0 X-SENDER: yxj@rock-chips.com X-DNS-TYPE: 0 Received: from localhost.localdomain (unknown [127.0.0.1]) by smtp.263.net (Postfix) whith ESMTP id 211920UT0DC; Thu, 04 Dec 2014 18:09:04 +0800 (CST) From: Andy Yan To: airlied@linux.ie, Philipp Zabel , heiko@sntech.de, fabio.estevam@freescale.com, rmk+kernel@arm.linux.org.uk Subject: [PATCH v17 09/12] drm: bridge/dw_hdmi: clear i2cmphy_stat0 reg in hdmi_phy_wait_i2c_done Date: Thu, 4 Dec 2014 18:08:44 +0800 Message-Id: <1417687724-13347-1-git-send-email-andy.yan@rock-chips.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1417686826-12687-1-git-send-email-andy.yan@rock-chips.com> References: <1417686826-12687-1-git-send-email-andy.yan@rock-chips.com> X-Mailman-Approved-At: Thu, 04 Dec 2014 17:38:25 -0800 Cc: Mark Rutland , dri-devel@lists.freedesktop.org, ykk@rock-chips.com, devel@driverdev.osuosl.org, Arnd Bergmann , linux-rockchip@lists.infradead.org, Grant Likely , Dave Airlie , jay.xu@rock-chips.com, devicetree@vger.kernel.org, Zubair.Kakakhel@imgtec.com, Pawel Moll , Ian Campbell , Rob Herring , mark.yao@rock-chips.com, Josh Boyer , Greg Kroah-Hartman , linux-kernel@vger.kernel.org, djkurtz@google.com, Kumar Gala , Andy Yan , vladimir_zapolskiy@mentor.com X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP HDMI_IH_I2CMPHY_STAT0 is a clear on write register, which indicates i2cm operation status(i2c transfer done or error), every hdmi phy register configuration must check this register to make sure the configuration has complete. But the indication bit should be cleared after check, otherwise the corresponding bit will hold on forever, this may give a wrong signal for next check. Signed-off-by: Andy Yan --- Changes in v17: None Changes in v16: None Changes in v15: None Changes in v14: None Changes in v13: None Changes in v12: None Changes in v11: None Changes in v10: None Changes in v9: None Changes in v8: None Changes in v7: None Changes in v6: None Changes in v5: None Changes in v4: None Changes in v3: None drivers/gpu/drm/bridge/dw_hdmi.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/bridge/dw_hdmi.c b/drivers/gpu/drm/bridge/dw_hdmi.c index 9119094..93bf5ca 100644 --- a/drivers/gpu/drm/bridge/dw_hdmi.c +++ b/drivers/gpu/drm/bridge/dw_hdmi.c @@ -666,11 +666,15 @@ static inline void hdmi_phy_test_dout(struct dw_hdmi *hdmi, static bool hdmi_phy_wait_i2c_done(struct dw_hdmi *hdmi, int msec) { - while ((hdmi_readb(hdmi, HDMI_IH_I2CMPHY_STAT0) & 0x3) == 0) { + u32 val; + + while ((val = hdmi_readb(hdmi, HDMI_IH_I2CMPHY_STAT0) & 0x3) == 0) { if (msec-- == 0) return false; udelay(1000); } + hdmi_writeb(hdmi, val, HDMI_IH_I2CMPHY_STAT0); + return true; }