From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752215AbdBMJ2f (ORCPT ); Mon, 13 Feb 2017 04:28:35 -0500 Received: from regular1.263xmail.com ([211.150.99.131]:49464 "EHLO regular1.263xmail.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751666AbdBMJ2a (ORCPT ); Mon, 13 Feb 2017 04:28:30 -0500 X-263anti-spam: KSV:0; X-MAIL-GRAY: 0 X-MAIL-DELIVERY: 1 X-KSVirus-check: 0 X-ABS-CHECKED: 4 X-RL-SENDER: wzz@rock-chips.com X-FST-TO: seanpaul@chromium.org X-SENDER-IP: 103.29.142.67 X-LOGIN-NAME: wzz@rock-chips.com X-UNIQUE-TAG: <21bb3a07976a36c5e81f98aa5f1478d9> X-ATTACHMENT-NUM: 0 X-DNS-TYPE: 0 From: zain wang To: Sean Paul , Daniel Vetter , Inki Dae , David Airlie Cc: Tomeu Vizoso , Mika Kahola , =?UTF-8?q?St=C3=A9phane=20Marchesin?= , Tomasz Figa , dianders@chromium.org, Thierry Reding , Heiko Stuebner , Jingoo Han , Javier Martinez Canillas , linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-samsung-soc@vger.kernel.org, linux-rockchip@lists.infradead.org, zain wang Subject: [PATCH] drm/bridge: analogix_dp: Don't return -EBUSY when msg->size is 0 in aux transaction Date: Mon, 13 Feb 2017 17:27:46 +0800 Message-Id: <1486978066-5351-1-git-send-email-wzz@rock-chips.com> X-Mailer: git-send-email 1.9.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The analogix_dp_transfer() will return -EBUSY if num_transferred is zero. But sometimes we will send a bare address packet to start the transaction, like drm_dp_i2c_xfer() show: ...... /* Send a bare address packet to start the transaction. * Zero sized messages specify an address only (bare * address) transaction. */ msg.buffer = NULL; msg.size = 0; err = drm_dp_i2c_do_msg(aux, &msg); ...... In this case, the msg->size is zero, so the num_transferred will be zero too. We can't return -EBUSY here, let's we return num_transferred if num_transferred equals msg->size. Signed-off-by: zain wang --- drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c index 303083a..5384aca 100644 --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c @@ -1162,5 +1162,5 @@ ssize_t analogix_dp_transfer(struct analogix_dp_device *dp, (msg->request & ~DP_AUX_I2C_MOT) == DP_AUX_NATIVE_READ) msg->reply = DP_AUX_NATIVE_REPLY_ACK; - return num_transferred > 0 ? num_transferred : -EBUSY; + return (num_transferred == msg->size) ? num_transferred : -EBUSY; } -- 1.9.1