From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753347AbcHHTsf (ORCPT ); Mon, 8 Aug 2016 15:48:35 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:35816 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753149AbcHHTOX (ORCPT ); Mon, 8 Aug 2016 15:14:23 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Michal Suchanek , Maxime Ripard , Mark Brown Subject: [PATCH 4.4 43/68] spi: sun4i: fix FIFO limit Date: Mon, 8 Aug 2016 21:11:18 +0200 Message-Id: <20160808180211.681204745@linuxfoundation.org> X-Mailer: git-send-email 2.9.2 In-Reply-To: <20160808180209.697765393@linuxfoundation.org> References: <20160808180209.697765393@linuxfoundation.org> User-Agent: quilt/0.64 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Michal Suchanek commit 6d9fe44bd73d567d04d3a68a2d2fa521ab9532f2 upstream. When testing SPI without DMA I noticed that filling the FIFO on the spi controller causes timeout. Always leave room for one byte in the FIFO. Signed-off-by: Michal Suchanek Acked-by: Maxime Ripard Signed-off-by: Mark Brown Signed-off-by: Greg Kroah-Hartman --- drivers/spi/spi-sun4i.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) --- a/drivers/spi/spi-sun4i.c +++ b/drivers/spi/spi-sun4i.c @@ -177,7 +177,10 @@ static int sun4i_spi_transfer_one(struct /* We don't support transfer larger than the FIFO */ if (tfr->len > SUN4I_FIFO_DEPTH) - return -EINVAL; + return -EMSGSIZE; + + if (tfr->tx_buf && tfr->len >= SUN4I_FIFO_DEPTH) + return -EMSGSIZE; reinit_completion(&sspi->done); sspi->tx_buf = tfr->tx_buf; @@ -270,8 +273,12 @@ static int sun4i_spi_transfer_one(struct sun4i_spi_write(sspi, SUN4I_BURST_CNT_REG, SUN4I_BURST_CNT(tfr->len)); sun4i_spi_write(sspi, SUN4I_XMIT_CNT_REG, SUN4I_XMIT_CNT(tx_len)); - /* Fill the TX FIFO */ - sun4i_spi_fill_fifo(sspi, SUN4I_FIFO_DEPTH); + /* + * Fill the TX FIFO + * Filling the FIFO fully causes timeout for some reason + * at least on spi2 on A10s + */ + sun4i_spi_fill_fifo(sspi, SUN4I_FIFO_DEPTH - 1); /* Enable the interrupts */ sun4i_spi_write(sspi, SUN4I_INT_CTL_REG, SUN4I_INT_CTL_TC);