From patchwork Wed Nov 26 13:34:30 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andy Yan X-Patchwork-Id: 5390791 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 3BE70C11AC for ; Thu, 27 Nov 2014 01:01:45 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 599AC201C7 for ; Thu, 27 Nov 2014 01:01:44 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) by mail.kernel.org (Postfix) with ESMTP id 713502010B for ; Thu, 27 Nov 2014 01:01:43 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id BEBE66E4AC; Wed, 26 Nov 2014 17:01:39 -0800 (PST) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from va-smtp01.263.net (va-smtp01.263.net [54.88.144.211]) by gabe.freedesktop.org (Postfix) with ESMTP id CC0956E389 for ; Wed, 26 Nov 2014 05:35:12 -0800 (PST) Received: from localhost.localdomain (localhost.localdomain [127.0.0.1]) by va-smtp01.263.net (Postfix) with ESMTP id 8F92A7F95D; Wed, 26 Nov 2014 13:34:54 +0000 (UTC) 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: <045c2e4346e8a422e5ac0797332399ff> X-ATTACHMENT-NUM: 0 X-SENDER: yxj@rock-chips.com X-DNS-TYPE: 1 Received: from localhost.localdomain (localhost [127.0.0.1]) by va-smtp01.263.net (Postfix) whith ESMTP id 29569DHLM2H; Wed, 26 Nov 2014 13:34:54 +0000 (UTC) From: Andy Yan To: airlied@linux.ie, Philipp Zabel , heiko@sntech.de, fabio.estevam@freescale.com, rmk+kernel@arm.linux.org.uk Subject: [PATCH v13 09/12] drm: bridge/dw_hdmi: clear i2cmphy_stat0 reg in hdmi_phy_wait_i2c_done Date: Wed, 26 Nov 2014 21:34:30 +0800 Message-Id: <1417008870-32362-1-git-send-email-andy.yan@rock-chips.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1417008157-31861-1-git-send-email-andy.yan@rock-chips.com> References: <1417008157-31861-1-git-send-email-andy.yan@rock-chips.com> X-Mailman-Approved-At: Wed, 26 Nov 2014 17:01:38 -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 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 v13: None Changes in v12: None Changes in v11: - split form patch 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 b13e782..8aa5f61 100644 --- a/drivers/gpu/drm/bridge/dw_hdmi.c +++ b/drivers/gpu/drm/bridge/dw_hdmi.c @@ -668,11 +668,15 @@ 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; }