From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AG47ELtQ5v9H6vdBCCyWvQ4TlfXBYbx5+KHjzHST+9DIyYggCZaDiB/4ZiixnfstQeVgpmTHhCkt ARC-Seal: i=1; a=rsa-sha256; t=1521483688; cv=none; d=google.com; s=arc-20160816; b=Ak7KAJbFz4CrGM9pOmhuEfVE57fitXarCePJyTfSdHHRxtNsYkqWXePXuturG69JXo VcqbliRTdSL2a3woH5ytOf8FQuundi3qaEOdylpqSNtoLj/vFiBcWyeqhb3Oyw6obAF/ 6Jz36NrsockEE5x2Htpl1bdi24yMQhs2ODoRxkwcqNHZ9zOaH3/qjCtcqJjyf/YkIDc6 d7ZVTmsjVGS06o298gjFejSao3Lg/QzkgKHQUWbEjJStxAmjDw0NjRFZaAhm5q9XevHP 2NqEq9tnjCO/j8+jfX1dIbrkrwQaYqegCt30il7HNCLVmtBkqD0XKSP+lJjau4I9pNE2 PSxA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=mime-version:user-agent:references:in-reply-to:message-id:date :subject:cc:to:from:arc-authentication-results; bh=VihABIU+AsGwm09SqpznluNQSjyX30Z2qkCqymLygck=; b=oK/+/xn/la/VijX6NDEKbYHUYFvZed0sf1WqkJvTY6bgav8LXNG7ZrJrpG5yHKCLxP w0k9twdrbeib8OFeebJwccYR9xnfBZ0ZonyU06SfjG5mkvOjQXACRR3Mz9gaIIR/eIHN HdOQVy8DUhOf/ZF9Xfm0E0gFTfJH3lpVuqsrAAxR3ezOwNKGQr0tvsXoE5ayuSe5MKYi ALm3IU8/DoPAicFE+eTLySv5pfH67XjKjRgaLJ94Qan0mEinxaVfhLj4NzxvhYvEUqAC EV8BhsOtkKWC+uvnkX/PfkxGYN4sFeviAhXvjwnvXzUHwo2mKPfdoXhjCeFgDkODKluX C1Ng== ARC-Authentication-Results: i=1; mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 90.92.61.202 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org Authentication-Results: mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 90.92.61.202 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Mark Brown , Akinobu Mita , Sasha Levin Subject: [PATCH 4.9 063/241] spi: omap2-mcspi: poll OMAP2_MCSPI_CHSTAT_RXS for PIO transfer Date: Mon, 19 Mar 2018 19:05:28 +0100 Message-Id: <20180319180753.809101115@linuxfoundation.org> X-Mailer: git-send-email 2.16.2 In-Reply-To: <20180319180751.172155436@linuxfoundation.org> References: <20180319180751.172155436@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-LABELS: =?utf-8?b?IlxcU2VudCI=?= X-GMAIL-THRID: =?utf-8?q?1595390520568953936?= X-GMAIL-MSGID: =?utf-8?q?1595391279573924350?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Akinobu Mita [ Upstream commit 812613591cb652344186c4cd912304ed02138566 ] When running the spi-loopback-test with slower clock rate like 10 KHz, the test for 251 bytes transfer was failed. This failure triggered an spi-omap2-mcspi's error message "DMA RX last word empty". This message means that PIO for reading the remaining bytes due to the DMA transfer length reduction is failed. This problem can be fixed by polling OMAP2_MCSPI_CHSTAT_RXS bit in channel status register to wait until the receive buffer register is filled. Cc: Mark Brown Signed-off-by: Akinobu Mita Signed-off-by: Mark Brown Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/spi/spi-omap2-mcspi.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) --- a/drivers/spi/spi-omap2-mcspi.c +++ b/drivers/spi/spi-omap2-mcspi.c @@ -454,6 +454,8 @@ omap2_mcspi_rx_dma(struct spi_device *sp int elements = 0; int word_len, element_count; struct omap2_mcspi_cs *cs = spi->controller_state; + void __iomem *chstat_reg = cs->base + OMAP2_MCSPI_CHSTAT0; + mcspi = spi_master_get_devdata(spi->master); mcspi_dma = &mcspi->dma_channels[spi->chip_select]; count = xfer->len; @@ -549,8 +551,8 @@ omap2_mcspi_rx_dma(struct spi_device *sp if (l & OMAP2_MCSPI_CHCONF_TURBO) { elements--; - if (likely(mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHSTAT0) - & OMAP2_MCSPI_CHSTAT_RXS)) { + if (!mcspi_wait_for_reg_bit(chstat_reg, + OMAP2_MCSPI_CHSTAT_RXS)) { u32 w; w = mcspi_read_cs_reg(spi, OMAP2_MCSPI_RX0); @@ -568,8 +570,7 @@ omap2_mcspi_rx_dma(struct spi_device *sp return count; } } - if (likely(mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHSTAT0) - & OMAP2_MCSPI_CHSTAT_RXS)) { + if (!mcspi_wait_for_reg_bit(chstat_reg, OMAP2_MCSPI_CHSTAT_RXS)) { u32 w; w = mcspi_read_cs_reg(spi, OMAP2_MCSPI_RX0);