From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1427987AbeCBNQy (ORCPT ); Fri, 2 Mar 2018 08:16:54 -0500 Received: from mx07-00178001.pphosted.com ([62.209.51.94]:7338 "EHLO mx07-00178001.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1424439AbeCBNQl (ORCPT ); Fri, 2 Mar 2018 08:16:41 -0500 From: Philippe CORNU To: Andrzej Hajda , Archit Taneja , Laurent Pinchart , David Airlie , "Brian Norris" , Benjamin Gaignard , Bhumika Goyal , "dri-devel@lists.freedesktop.org" , "linux-kernel@vger.kernel.org" , Sandy Huang , Heiko Stubner , "linux-arm-kernel@lists.infradead.org" , "linux-rockchip@lists.infradead.org" CC: Yannick FERTRE , Vincent ABRIOU , Alexandre TORGUE Subject: Re: [PATCH] drm/bridge/synopsys: dsi: readl_poll_timeout return value clean up Thread-Topic: [PATCH] drm/bridge/synopsys: dsi: readl_poll_timeout return value clean up Thread-Index: AQHTngA8EO6d0iime02JI6Vf5496FaO7Kq8AgAGo+oCAADC8gA== Date: Fri, 2 Mar 2018 13:15:49 +0000 Message-ID: <587f8a32-b9b3-0e81-d91d-69ea256bdc29@st.com> References: <20180204213624.18288-1-philippe.cornu@st.com> <172e7f68-8f4b-7e5f-3e9f-7aaf10a51dc9@st.com> <290c749a-70bf-2b74-1fb9-2de26708d001@samsung.com> In-Reply-To: <290c749a-70bf-2b74-1fb9-2de26708d001@samsung.com> Accept-Language: fr-FR, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: user-agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.6.0 x-ms-exchange-messagesentrepresentingtype: 1 x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [10.75.127.48] Content-Type: text/plain; charset="utf-8" Content-ID: MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2018-03-02_07:,, signatures=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from base64 to 8bit by mail.home.local id w22DH1N8025759 Hi Andrzej, On 03/02/2018 11:21 AM, Andrzej Hajda wrote: > On 01.03.2018 10:00, Philippe CORNU wrote: >> Hi Archit, Andrzej & Laurent, >> >> May I ask you please your feedback on this small patch? >> Many thanks, >> >> Philippe :-) >> >> On 02/04/2018 10:36 PM, Philippe Cornu wrote: >>> The readl_poll_timeout() return value is 0 in case of success >>> so it is better to detect errors without taking care of the >>> return value sign. >>> >>> Signed-off-by: Philippe Cornu > > The patch is of course correct. However I am not sure if necessary. For > sure functionally it does not change anything. > AFAIK kernel CodingStyle says nothing about it, so I suppose it is > matter of personal taste. I sent this tiny patch in order to homogenize the dw mipi driver because there were both cases "if (ret)" & "if (ret < 0)" in the source code. I did not really find a preferred way in the kernel source code so I selected what sounds the best to me ie "if (ret)" but it is not a problem to make another patch for "if (ret < 0)" everywhere :-) In any case, the most important from my pov is to have a homogeneous source code :-) Does anyone have a preferred choice between "if (ret)" & "if (ret < 0)" after a "ret = readl_poll_timeout()"? > Anyway I can give it: > Reviewed-by: Andrzej Hajda Many thanks, Philippe :) > >  -- > Regards > Andrzej > >>> --- >>> drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c | 10 +++++----- >>> 1 file changed, 5 insertions(+), 5 deletions(-) >>> >>> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c >>> index 65aeb3f78b48..4d0e8471a15c 100644 >>> --- a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c >>> +++ b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c >>> @@ -342,7 +342,7 @@ static int dw_mipi_dsi_gen_pkt_hdr_write(struct dw_mipi_dsi *dsi, u32 hdr_val) >>> ret = qq(dsi->base + DSI_CMD_PKT_STATUS, >>> val, !(val & GEN_CMD_FULL), 1000, >>> CMD_PKT_STATUS_TIMEOUT_US); >>> - if (ret < 0) { >>> + if (ret) { >>> dev_err(dsi->dev, "failed to get available command FIFO\n"); >>> return ret; >>> } >>> @@ -353,7 +353,7 @@ static int dw_mipi_dsi_gen_pkt_hdr_write(struct dw_mipi_dsi *dsi, u32 hdr_val) >>> ret = readl_poll_timeout(dsi->base + DSI_CMD_PKT_STATUS, >>> val, (val & mask) == mask, >>> 1000, CMD_PKT_STATUS_TIMEOUT_US); >>> - if (ret < 0) { >>> + if (ret) { >>> dev_err(dsi->dev, "failed to write command FIFO\n"); >>> return ret; >>> } >>> @@ -385,7 +385,7 @@ static int dw_mipi_dsi_write(struct dw_mipi_dsi *dsi, >>> ret = readl_poll_timeout(dsi->base + DSI_CMD_PKT_STATUS, >>> val, !(val & GEN_PLD_W_FULL), 1000, >>> CMD_PKT_STATUS_TIMEOUT_US); >>> - if (ret < 0) { >>> + if (ret) { >>> dev_err(dsi->dev, >>> "failed to get available write payload FIFO\n"); >>> return ret; >>> @@ -716,13 +716,13 @@ static void dw_mipi_dsi_dphy_enable(struct dw_mipi_dsi *dsi) >>> >>> ret = readl_poll_timeout(dsi->base + DSI_PHY_STATUS, val, >>> val & PHY_LOCK, 1000, PHY_STATUS_TIMEOUT_US); >>> - if (ret < 0) >>> + if (ret) >>> DRM_DEBUG_DRIVER("failed to wait phy lock state\n"); >>> >>> ret = readl_poll_timeout(dsi->base + DSI_PHY_STATUS, >>> val, val & PHY_STOP_STATE_CLK_LANE, 1000, >>> PHY_STATUS_TIMEOUT_US); >>> - if (ret < 0) >>> + if (ret) >>> DRM_DEBUG_DRIVER("failed to wait phy clk lane stop state\n"); >>> } >>> > >