From mboxrd@z Thu Jan 1 00:00:00 1970 From: Russell King - ARM Linux admin Subject: [BUG] vf610-zii-dev-rev-b SPI fails at boot Date: Thu, 21 Feb 2019 15:24:59 +0000 Message-ID: <20190221152459.axrjce7yqkjmedgl@shell.armlinux.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-arm-kernel@lists.infradead.org, Mark Brown , linux-spi@vger.kernel.org, Lorenzo Bianconi Return-path: Content-Disposition: inline List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org List-Id: linux-spi.vger.kernel.org While booting 4.20 on the ZII development revision B board, I notice this in the kernel logs: spi spi0.1: setup: unsupported mode bits 4 spi_gpio spi0: can't setup spi0.1, status -22 spi_master spi0: spi_device register error /spi0/at93c46d@1 spi_master spi0: Failed to create SPI device for /spi0/at93c46d@1 This is for the at93c46d@1 device attached to spi-gpio (see arch/arm/boot/dts/vf610-zii-dev-rev-b.dts around line 330). This is declared with "spi-cs-high;" in DT. It appears to be complaining about the SPI_CS_HIGH flag. It appears this warning comes from drivers/spi/spi.c around lines 2828-2847 due to: bad_bits = spi->mode & ~(spi->controller->mode_bits | SPI_CS_WORD); and it looks like spi-gpio sets: master->mode_bits = SPI_3WIRE | SPI_CPHA | SPI_CPOL; but then goes on to set: spi_gpio->bitbang.flags = SPI_CS_HIGH; However, this is ignored by bitbang if master->mode_bits has already been set: if (!master->mode_bits) master->mode_bits = SPI_CPOL | SPI_CPHA | bitbang->flags; It looks like this commit introduced for v4.19 broke the driver: commit 4b859db2c60692560afbfef1b030d0ddef57b7ee Author: Lorenzo Bianconi Date: Sat Jul 28 10:19:14 2018 +0200 by setting master->mode_bits - prior to this, bitbang would have set the mode bits itself. -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTC broadband for 0.8mile line in suburbia: sync at 12.1Mbps down 622kbps up According to speedtest.net: 11.9Mbps down 500kbps up