From patchwork Tue Apr 23 20:15:13 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Martin Sperl X-Patchwork-Id: 10913719 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id C6EFA1515 for ; Tue, 23 Apr 2019 20:15:45 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B982E288EE for ; Tue, 23 Apr 2019 20:15:45 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id B7EE3288FA; Tue, 23 Apr 2019 20:15:45 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 41B47288EE for ; Tue, 23 Apr 2019 20:15:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726342AbfDWUPp (ORCPT ); Tue, 23 Apr 2019 16:15:45 -0400 Received: from 212-186-180-163.static.upcbusiness.at ([212.186.180.163]:33362 "EHLO cgate.sperl.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725956AbfDWUPo (ORCPT ); Tue, 23 Apr 2019 16:15:44 -0400 Received: from hc1.intern.sperl.org (account martin@sperl.org [10.10.10.59] verified) by sperl.org (CommuniGate Pro SMTP 6.2.1 _community_) with ESMTPSA id 7763609; Tue, 23 Apr 2019 20:15:33 +0000 From: kernel@martin.sperl.org To: Mark Brown , Eric Anholt , Stefan Wahren , linux-spi@vger.kernel.org, linux-rpi-kernel@lists.infradead.org, linux-arm-kernel@lists.infradead.org Cc: Martin Sperl Subject: [PATCH V2 6/6] spi: bcm2835: add driver stats to debugfs Date: Tue, 23 Apr 2019 20:15:13 +0000 Message-Id: <20190423201513.8073-7-kernel@martin.sperl.org> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20190423201513.8073-1-kernel@martin.sperl.org> References: <20190423201513.8073-1-kernel@martin.sperl.org> Sender: linux-spi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-spi@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Martin Sperl To estimate efficiency add statistics on transfer types (polling, interrupt and dma) used to debugfs. Signed-off-by: Martin Sperl Changelog: V1 -> V2: applied feedback by Stefan Wahren reorganized patchset added extra rational, descriptions fixed compile issue when CONFIG_DEBUG_FS is unset --- drivers/spi/spi-bcm2835.c | 74 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 74 insertions(+) -- 2.11.0 diff --git a/drivers/spi/spi-bcm2835.c b/drivers/spi/spi-bcm2835.c index 755e1e6d2252..83a67eb76325 100644 --- a/drivers/spi/spi-bcm2835.c +++ b/drivers/spi/spi-bcm2835.c @@ -22,6 +22,7 @@ #include #include +#include #include #include #include @@ -106,6 +107,15 @@ MODULE_PARM_DESC(dma_min_bytes_limit, * length is not a multiple of 4 (to overcome hardware limitation) * @tx_spillover: whether @tx_prologue spills over to second TX sglist entry * @dma_pending: whether a DMA transfer is in progress + * @debugfs_dir: the debugfs directory - neede to remove debugfs when + * unloading the module + * @count_transfer_polling: count of how often polling mode is used + * @count_transfer_irq: count of how often interrupt mode is used + * @count_transfer_irq_after_polling: count of how often we fall back to + * interrupt mode after starting in polling mode. + * These are counted as well in @count_transfer_polling and + * @count_transfer_irq + * @count_transfer_dma: count how often dma mode is used */ struct bcm2835_spi { void __iomem *regs; @@ -120,8 +130,55 @@ struct bcm2835_spi { int rx_prologue; unsigned int tx_spillover; unsigned int dma_pending; + + struct dentry *debugfs_dir; + u64 count_transfer_polling; + u64 count_transfer_irq; + u64 count_transfer_irq_after_polling; + u64 count_transfer_dma; }; +#if defined(CONFIG_DEBUG_FS) +static void bcm2835_debugfs_create(struct bcm2835_spi *bs, + const char *dname) +{ + char name[64]; + struct dentry *dir; + + /* get full name */ + snprintf(name, sizeof(name), "spi-bcm2835-%s", dname); + + /* the base directory */ + dir = debugfs_create_dir(name, NULL); + bs->debugfs_dir = dir; + + /* the counters */ + debugfs_create_u64("count_transfer_polling", 0444, dir, + &bs->count_transfer_polling); + debugfs_create_u64("count_transfer_irq", 0444, dir, + &bs->count_transfer_irq); + debugfs_create_u64("count_transfer_irq_after_polling", 0444, dir, + &bs->count_transfer_irq_after_polling); + debugfs_create_u64("count_transfer_dma", 0444, dir, + &bs->count_transfer_dma); +} + +static void bcm2835_debugfs_remove(struct bcm2835_spi *bs) +{ + debugfs_remove_recursive(bs->debugfs_dir); + bs->debugfs_dir = NULL; +} +#else +static void bcm2835_debugfs_create(struct bcm2835_spi *bs, + const char *dname) +{ +} + +static void bcm2835_debugfs_remove(struct bcm2835_spi *bs) +{ +} +#endif /* CONFIG_DEBUG_FS */ + static inline u32 bcm2835_rd(struct bcm2835_spi *bs, unsigned reg) { return readl(bs->regs + reg); @@ -325,6 +382,9 @@ static int bcm2835_spi_transfer_one_irq(struct spi_master *master, { struct bcm2835_spi *bs = spi_master_get_devdata(master); + /* update usage statistics */ + bs->count_transfer_irq++; + /* * Enable HW block, but with interrupts still disabled. * Otherwise the empty TX FIFO would immediately trigger an interrupt. @@ -583,6 +643,9 @@ static int bcm2835_spi_transfer_one_dma(struct spi_master *master, struct bcm2835_spi *bs = spi_master_get_devdata(master); int ret; + /* update usage statistics */ + bs->count_transfer_dma++; + /* * Transfer first few bytes without DMA if length of first TX or RX * sglist entry is not a multiple of 4 bytes (hardware limitation). @@ -739,6 +802,9 @@ static int bcm2835_spi_transfer_one_poll(struct spi_master *master, struct bcm2835_spi *bs = spi_master_get_devdata(master); unsigned long timeout; + /* update usage statistics */ + bs->count_transfer_polling++; + /* enable HW block without interrupts */ bcm2835_wr(bs, BCM2835_SPI_CS, cs | BCM2835_SPI_CS_TA); @@ -768,6 +834,10 @@ static int bcm2835_spi_transfer_one_poll(struct spi_master *master, jiffies - timeout, bs->tx_len, bs->rx_len); /* fall back to interrupt mode */ + + /* update usage statistics */ + bs->count_transfer_irq_after_polling++; + return bcm2835_spi_transfer_one_irq(master, spi, tfr, cs, false); } @@ -1004,6 +1074,8 @@ static int bcm2835_spi_probe(struct platform_device *pdev) goto out_clk_disable; } + bcm2835_debugfs_create(bs, dev_name(&pdev->dev)); + return 0; out_clk_disable: @@ -1018,6 +1090,8 @@ static int bcm2835_spi_remove(struct platform_device *pdev) struct spi_master *master = platform_get_drvdata(pdev); struct bcm2835_spi *bs = spi_master_get_devdata(master); + bcm2835_debugfs_remove(bs); + /* Clear FIFOs, and disable the HW block */ bcm2835_wr(bs, BCM2835_SPI_CS, BCM2835_SPI_CS_CLEAR_RX | BCM2835_SPI_CS_CLEAR_TX);