From mboxrd@z Thu Jan 1 00:00:00 1970 From: Brian Masney Subject: Re: [PATCH 05/11] drm/bridge: analogix-anx78xx: correct value of TX_P0 Date: Mon, 16 Sep 2019 06:40:04 -0400 Message-ID: <20190916104004.GB1644@onstation.org> References: <20190815004854.19860-1-masneyb@onstation.org> <20190815004854.19860-6-masneyb@onstation.org> <98199a9b-f7e0-ef95-62d7-401273457692@collabora.com> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit Return-path: Content-Disposition: inline In-Reply-To: <98199a9b-f7e0-ef95-62d7-401273457692@collabora.com> Sender: linux-kernel-owner@vger.kernel.org To: Enric Balletbo i Serra Cc: Andrzej Hajda , bjorn.andersson@linaro.org, robh+dt@kernel.org, agross@kernel.org, narmstrong@baylibre.com, robdclark@gmail.com, sean@poorly.run, airlied@linux.ie, daniel@ffwll.ch, mark.rutland@arm.com, Laurent.pinchart@ideasonboard.com, jonas@kwiboo.se, jernej.skrabec@siol.net, linus.walleij@linaro.org, dri-devel@lists.freedesktop.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, freedreno@lists.freedesktop.org List-Id: devicetree@vger.kernel.org On Mon, Sep 16, 2019 at 12:36:19PM +0200, Enric Balletbo i Serra wrote: > Hi Andrzej and Brian > > On 16/9/19 12:02, Andrzej Hajda wrote: > > On 15.08.2019 02:48, Brian Masney wrote: > >> When attempting to configure this driver on a Nexus 5 phone (msm8974), > >> setting up the dummy i2c bus for TX_P0 would fail due to an -EBUSY > >> error. The downstream MSM kernel sources [1] shows that the proper value > >> for TX_P0 is 0x78, not 0x70, so correct the value to allow device > >> probing to succeed. > >> > >> [1] https://github.com/AICP/kernel_lge_hammerhead/blob/n7.1/drivers/video/slimport/slimport_tx_reg.h > >> > >> Signed-off-by: Brian Masney > >> --- > >> drivers/gpu/drm/bridge/analogix-anx78xx.h | 2 +- > >> 1 file changed, 1 insertion(+), 1 deletion(-) > >> > >> diff --git a/drivers/gpu/drm/bridge/analogix-anx78xx.h b/drivers/gpu/drm/bridge/analogix-anx78xx.h > >> index 25e063bcecbc..bc511fc605c9 100644 > >> --- a/drivers/gpu/drm/bridge/analogix-anx78xx.h > >> +++ b/drivers/gpu/drm/bridge/analogix-anx78xx.h > >> @@ -6,7 +6,7 @@ > >> #ifndef __ANX78xx_H > >> #define __ANX78xx_H > >> > >> -#define TX_P0 0x70 > >> +#define TX_P0 0x78 > > > > > > This bothers me little. There are no upstream users, grepping android > > sources suggests that both values can be used [1][2]  (grep for "#define > > TX_P0"), moreover there is code suggesting both values can be valid [3]. > > > > Could you verify datasheet which i2c slave addresses are valid for this > > chip, if both I guess this patch should be reworked. > > > > On my case the valid i2c slave address is 0x70 (from datasheet, very sorry I > can't share it) and the bridge used is an ANX7814, it could be that ANX7808 or > ANX7812 have different slave addresses? I haven't been able to find any of the datasheets for these devices online. Product briefs are online (such as https://www.analogix.com/en/system/files/ANX7808_product_brief.pdf), but they don't provide this type of information. Brian