From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752269AbeDCP3R (ORCPT ); Tue, 3 Apr 2018 11:29:17 -0400 Received: from smtp54.i.mail.ru ([217.69.128.34]:56098 "EHLO smtp54.i.mail.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751685AbeDCP3N (ORCPT ); Tue, 3 Apr 2018 11:29:13 -0400 From: Sergey Suloev To: Mark Brown , Maxime Ripard , Chen-Yu Tsai Cc: linux-spi@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Sergey Suloev Subject: [PATCH v2 2/6] spi: sun4i: restrict transfer length in PIO-mode Date: Tue, 3 Apr 2018 18:29:01 +0300 Message-Id: <20180403152905.1524-3-ssuloev@orpaltech.com> X-Mailer: git-send-email 2.16.2 In-Reply-To: <20180403152905.1524-1-ssuloev@orpaltech.com> References: <20180403152905.1524-1-ssuloev@orpaltech.com> Authentication-Results: smtp54.i.mail.ru; auth=pass smtp.auth=ssuloev@orpaltech.com smtp.mailfrom=ssuloev@orpaltech.com X-7FA49CB5: 0D63561A33F958A5C5F1A375E31CFE67FD153644D6503B584944821BD68A5976725E5C173C3A84C3A1C30C8AFC676C8BE05AEED214505ADB42F54486E6D6388DC4224003CC836476C0CAF46E325F83A50BF2EBBBDD9D6B0F05F538519369F3743B503F486389A921A5CC5B56E945C8DA X-Mailru-Sender: C5364AD02485212F3ACDC11E67D849178F89E4B4913BFFC4ED2FA081347DF743069BFC61DABEEB110841D3AAAB1726C63DDE9B364B0DF289264D2CD8C2503E8C22A194DADEED8EEDCA01A23BA9CD1BE7ED14614B50AE0675 X-Mras: OK Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org There is no need to handle the 3/4 FIFO empty interrupt as the maximum supported transfer length in PIO mode is 64 bytes. As long as a problem was reported previously with filling FIFO on A10s we want to stick with 63 bytes depth. Changes in v2: 1) Restored processing of 3/4 FIFO full interrupt. Signed-off-by: Sergey Suloev --- drivers/spi/spi-sun4i.c | 37 ++++++++++--------------------------- 1 file changed, 10 insertions(+), 27 deletions(-) diff --git a/drivers/spi/spi-sun4i.c b/drivers/spi/spi-sun4i.c index 4141003..08fd007 100644 --- a/drivers/spi/spi-sun4i.c +++ b/drivers/spi/spi-sun4i.c @@ -22,7 +22,12 @@ #include -#define SUN4I_FIFO_DEPTH 64 +/* + * FIFO length is 64 bytes + * But filling the FIFO fully might cause a timeout + * on some devices, for example on spi2 on A10s + */ +#define SUN4I_FIFO_DEPTH 63 #define SUN4I_RXDATA_REG 0x00 @@ -202,7 +207,7 @@ static void sun4i_spi_set_cs(struct spi_device *spi, bool enable) static size_t sun4i_spi_max_transfer_size(struct spi_device *spi) { - return SUN4I_FIFO_DEPTH - 1; + return SUN4I_FIFO_DEPTH; } static int sun4i_spi_transfer_one(struct spi_master *master, @@ -216,11 +221,8 @@ static int sun4i_spi_transfer_one(struct spi_master *master, int ret = 0; u32 reg; - /* We don't support transfer larger than the FIFO */ - if (tfr->len > SUN4I_MAX_XFER_SIZE) - return -EMSGSIZE; - - if (tfr->tx_buf && tfr->len >= SUN4I_MAX_XFER_SIZE) + /* We don't support transfers larger than FIFO depth */ + if (tfr->len > SUN4I_FIFO_DEPTH) return -EMSGSIZE; reinit_completion(&sspi->done); @@ -313,17 +315,12 @@ static int sun4i_spi_transfer_one(struct spi_master *master, /* * 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); + sun4i_spi_fill_fifo(sspi, SUN4I_FIFO_DEPTH); /* Enable the interrupts */ sun4i_spi_enable_interrupt(sspi, SUN4I_INT_CTL_TC | SUN4I_INT_CTL_RF_F34); - /* Only enable Tx FIFO interrupt if we really need it */ - if (tx_len > SUN4I_FIFO_DEPTH) - sun4i_spi_enable_interrupt(sspi, SUN4I_INT_CTL_TF_E34); /* Start the transfer */ reg = sun4i_spi_read(sspi, SUN4I_CTL_REG); @@ -371,20 +368,6 @@ static irqreturn_t sun4i_spi_handler(int irq, void *dev_id) return IRQ_HANDLED; } - /* Transmit FIFO 3/4 empty */ - if (status & SUN4I_INT_CTL_TF_E34) { - sun4i_spi_fill_fifo(sspi, SUN4I_FIFO_DEPTH); - - if (!sspi->len) - /* nothing left to transmit */ - sun4i_spi_disable_interrupt(sspi, SUN4I_INT_CTL_TF_E34); - - /* Only clear the interrupt _after_ re-seeding the FIFO */ - sun4i_spi_write(sspi, SUN4I_INT_STA_REG, SUN4I_INT_CTL_TF_E34); - - return IRQ_HANDLED; - } - return IRQ_NONE; } -- 2.16.2