From patchwork Tue Dec 2 07:43:44 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andy Yan X-Patchwork-Id: 5420101 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 2EBC2BEEA8 for ; Tue, 2 Dec 2014 13:04:09 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 628A620225 for ; Tue, 2 Dec 2014 13:04:08 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) by mail.kernel.org (Postfix) with ESMTP id 862E2201CE for ; Tue, 2 Dec 2014 13:04:07 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 2480F6E8D3; Tue, 2 Dec 2014 05:03:52 -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 F16DF6E3F2 for ; Mon, 1 Dec 2014 23:44:15 -0800 (PST) Received: from andy.yan?rock-chips.com (unknown [192.168.167.131]) by lucky1.263xmail.com (Postfix) with SMTP id 15A81FFB3; Tue, 2 Dec 2014 15:44:13 +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 2C540451; Tue, 2 Dec 2014 15:44:09 +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: 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 4346UJJFIN; Tue, 02 Dec 2014 15:44:12 +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 v15 09/12] drm: bridge/dw_hdmi: clear i2cmphy_stat0 reg in hdmi_phy_wait_i2c_done Date: Tue, 2 Dec 2014 15:43:44 +0800 Message-Id: <1417506224-18766-1-git-send-email-andy.yan@rock-chips.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1417505778-18341-1-git-send-email-andy.yan@rock-chips.com> References: <1417505778-18341-1-git-send-email-andy.yan@rock-chips.com> X-Mailman-Approved-At: Tue, 02 Dec 2014 05:03:48 -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 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 65cb077..13ace4e 100644 --- a/drivers/gpu/drm/bridge/dw_hdmi.c +++ b/drivers/gpu/drm/bridge/dw_hdmi.c @@ -663,11 +663,15 @@ 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; }