From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754300AbbLWGAx (ORCPT ); Wed, 23 Dec 2015 01:00:53 -0500 Received: from lucky1.263xmail.com ([211.157.147.130]:38221 "EHLO lucky1.263xmail.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751503AbbLWGAv (ORCPT ); Wed, 23 Dec 2015 01:00:51 -0500 X-263anti-spam: KSV:0; X-MAIL-GRAY: 1 X-MAIL-DELIVERY: 0 X-KSVirus-check: 0 X-ABS-CHECKED: 4 X-ADDR-CHECKED: 0 X-RL-SENDER: ykk@rock-chips.com X-FST-TO: linux-arm-kernel@lists.infradead.org X-SENDER-IP: 58.22.7.114 X-LOGIN-NAME: ykk@rock-chips.com X-UNIQUE-TAG: X-ATTACHMENT-NUM: 0 X-DNS-TYPE: 0 Subject: Re: [PATCH v11 17/19] drm: bridge: analogix/dp: expand the look time for waiting AUX CH reply To: Jingoo Han , "'Inki Dae'" , "'Mark Yao'" , "'Heiko Stuebner'" References: <1450236018-1118-1-git-send-email-ykk@rock-chips.com> <1450238257-3274-1-git-send-email-ykk@rock-chips.com> <000a01d13cb4$0f81f510$2e85df30$@com> <567A21EC.4010003@rock-chips.com> Cc: devicetree@vger.kernel.org, "'Krzysztof Kozlowski'" , linux-samsung-soc@vger.kernel.org, "'Russell King'" , linux-rockchip@lists.infradead.org, emil.l.velikov@gmail.com, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, "'Kishon Vijay Abraham I'" , javier@osg.samsung.com, "'Rob Herring'" , "'Andy Yan'" , "'Thierry Reding'" , "'Gustavo Padovan'" , linux-arm-kernel@lists.infradead.org From: Yakir Yang Message-ID: <567A3882.3020808@rock-chips.com> Date: Wed, 23 Dec 2015 14:00:34 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.3.0 MIME-Version: 1.0 In-Reply-To: <567A21EC.4010003@rock-chips.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Jingoo, On 12/23/2015 12:24 PM, Yakir Yang wrote: > Hi Jingoo, > > On 12/22/2015 08:26 PM, Jingoo Han wrote: >> On Wednesday, December 16, 2015 12:58 PM, Yakir Yang wrote: >>> After test on rockchiop platform, i found sometims driver would failed >>> at reading EDID message. After debugging more, i found that it's okay >>> to read_a byte from i2c, but it would failed at AUX transcation if we >>> try to ready multi-bytes from i2c. >>> >>> Driver just can't received the AUX CH reply command, even no AUX error >>> code. I may guess that the AUX wait time is not enough, so I try to >>> expand the AUX wait time, and i do see this could fix the EDID read >>> failed at rockchip platform. >>> >>> And I thought that expand the wait time won't hurt Exynos platform too >>> much, cause Exynos didn't have this problem, then driver would received >>> the reply command very soon, so no more additional wait time would >>> bring >>> to Exynos platform. >>> >>> Signed-off-by: Yakir Yang >>> --- >>> 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 >>> Changes in v2: None >>> >>> 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 c7e2959..dc376bd 100644 >>> --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c >>> +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c >>> @@ -482,7 +482,7 @@ int analogix_dp_start_aux_transaction(struct >>> analogix_dp_device *dp) >>> reg = readl(dp->reg_base + ANALOGIX_DP_INT_STA); >>> while (!(reg & RPLY_RECEIV)) { >>> timeout_loop++; >>> - if (DP_TIMEOUT_LOOP_COUNT < timeout_loop) { >>> + if (DP_TIMEOUT_LOOP_COUNT * 10 < timeout_loop) { >> No, I hate this coding. >> analogix_dp_reg.c is the common code that can be shared by various SoCs. >> Please, find another way. > > Okay, I have double checked that i do have this problem in my side. > Hmmm..... > I thought it's okay for you if I expand the "DP_TIMEOUT_LOOP_COUNT" > directly, > it won't hurt Exynos platform too much, cause Exynos didn't have this > problem, > then driver would received,the reply command very soon, so no more > additional > wait time would bring to Exynos platform. > Oh, sorry, little mistaken, I mean, is it okay for you to expand the "DP_TIMEOUT_LOOP_COUNT" directly ? - Yakir > And actually the datasheet haven't described the spec of aux reply > delay time. > > Thanks, > - Yakir > >> Best regards, >> Jingoo Han >> >> >>> dev_err(dp->dev, "AUX CH command reply failed!\n"); >>> return -ETIMEDOUT; >>> } >>> -- >>> 1.9.1 >> >> >> >> > > > > _______________________________________________ > Linux-rockchip mailing list > Linux-rockchip@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-rockchip > > >