From mboxrd@z Thu Jan 1 00:00:00 1970 From: thierry.reding@gmail.com (Thierry Reding) Date: Mon, 9 Jul 2018 16:01:10 +0200 Subject: [PATCH] ARM: tegra: Fix Tegra30 Cardhu PCA954x reset In-Reply-To: <1530608387-9591-1-git-send-email-jonathanh@nvidia.com> References: <1530608387-9591-1-git-send-email-jonathanh@nvidia.com> Message-ID: <20180709140110.GA18353@ulmo> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Tue, Jul 03, 2018 at 09:59:47AM +0100, Jon Hunter wrote: > On all versions of Tegra30 Cardhu, the reset signal to the NXP PCA9546 > I2C mux is connected to the Tegra GPIO BB0. Currently, this pin on the > Tegra is not configured as a GPIO but as a special-function IO (SFIO) > that is multiplexing the pin to an I2S controller. On exiting system > suspend, I2C commands sent to the PCA9546 are failing because there is > no ACK. Although it is not possible to see exactly what is happening > to the reset during suspend, by ensuring it is configured as a GPIO > and driven high, to de-assert the reset, the failures are no longer > seen. > > Please note that this GPIO is also used to drive the reset signal > going to the camera connector on the board. However, given that there > is no camera support currently for Cardhu, this should not have any > impact. > > Fixes: 40431d16ff11 ("ARM: tegra: enable PCA9546 on Cardhu") > > Cc: stable at vger.kernel.org > > Signed-off-by: Jon Hunter > --- > arch/arm/boot/dts/tegra30-cardhu.dtsi | 1 + > 1 file changed, 1 insertion(+) Applied to for-4.19/arm/dt, thanks. Thierry -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 833 bytes Desc: not available URL: