From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D63F014460C; Tue, 16 Jan 2024 19:56:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705434969; cv=none; b=tw+Ym906i6TuxXWDGty0VQS/5lAnL8OYSxNqzF8+GxFVTvxSUQP+0752VC2rX5+B/lN8zkfuCkN1Obn4OCJirp6zeE0EUMbXMkSs7kUcNs1c+ol/XWLY+w5LmfawPDhHwrSpZzDo1fPRd0R9yCKze82C/TxXqrBJ0mRqU1fB5m4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705434969; c=relaxed/simple; bh=jg6VgF/EuOdf/AZ8IrPRAm/o2oDTU1Re8n9z1HgWtrI=; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID: X-Mailer:In-Reply-To:References:MIME-Version:X-stable: X-Patchwork-Hint:X-stable-base:Content-Transfer-Encoding; b=HH4RVGy/xjmxHuMgu7BPpm+3tsVT/1KaB4jIMzNXlVextnNBwHB/MW7dCoBXjywZXls31zCaWSchfe02X/z+5IxXKzzlmydpUaOndsrjc78qhCZhwQHaR0oQkd75472u+s/Hjy2WUxhAIx4c9DR9RqwKloCzLKb90BYll9RPyzo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=g9ItLq17; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="g9ItLq17" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D9D56C433C7; Tue, 16 Jan 2024 19:56:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1705434969; bh=jg6VgF/EuOdf/AZ8IrPRAm/o2oDTU1Re8n9z1HgWtrI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=g9ItLq17nfv+2vrPCictRNtxGJ59B1Z2qEHyPBXI0XHpcWnytHdFrD0KsKY8F1w0Q KA6OJnB74O1dKKhaSn23C4ZbuVItdT3QuAf9sRf/lNr3bmsz5PJe5dRSvBMlGe6mrh dttxy9UBFfoTT0fXqrBhniiaveyEiLwScGkYhXAw6klVN5UFfYJWYn2Ip2hDVQvQhh YB6L7GdPzKyPlbK91y2wTOKsE8nxR2yMJQMLH0fvgMs4aKbLQjBSHr0GHQOdG1wbnU TfApekrIVKFGgFQ7VLuw/ibsiHvL66skuVTwcDfIhZW3Ot5ZkKMMriMwnMYUwaqT+u p0CqMQdi0v8kg== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Tobias Waldekranz , Andrew Lunn , Jakub Kicinski , Sasha Levin , davem@davemloft.net, edumazet@google.com, pabeni@redhat.com, horms@kernel.org, robh@kernel.org, u.kleine-koenig@pengutronix.de, krzysztof.kozlowski@linaro.org, netdev@vger.kernel.org Subject: [PATCH AUTOSEL 6.1 26/68] net: mvmdio: Avoid excessive sleeps in polled mode Date: Tue, 16 Jan 2024 14:53:25 -0500 Message-ID: <20240116195511.255854-26-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240116195511.255854-1-sashal@kernel.org> References: <20240116195511.255854-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.1.73 Content-Transfer-Encoding: 8bit From: Tobias Waldekranz [ Upstream commit 7dd12fe34686d89c332b1a05104d18d728591f0a ] Before this change, when operating in polled mode, i.e. no IRQ is available, every individual C45 access would be hit with a 150us sleep after the bus access. For example, on a board with a CN9130 SoC connected to an MV88X3310 PHY, a single C45 read would take around 165us: root@infix:~$ mdio f212a600.mdio-mii mmd 4:1 bench 0xc003 Performed 1000 reads in 165ms By replacing the long sleep with a tighter poll loop, we observe a 10x increase in bus throughput: root@infix:~$ mdio f212a600.mdio-mii mmd 4:1 bench 0xc003 Performed 1000 reads in 15ms Signed-off-by: Tobias Waldekranz Reviewed-by: Andrew Lunn Tested-by: Andrew Lunn Link: https://lore.kernel.org/r/20231204100811.2708884-3-tobias@waldekranz.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- drivers/net/ethernet/marvell/mvmdio.c | 53 ++++++++------------------- 1 file changed, 16 insertions(+), 37 deletions(-) diff --git a/drivers/net/ethernet/marvell/mvmdio.c b/drivers/net/ethernet/marvell/mvmdio.c index ef878973b859..b4c576e79a95 100644 --- a/drivers/net/ethernet/marvell/mvmdio.c +++ b/drivers/net/ethernet/marvell/mvmdio.c @@ -23,6 +23,7 @@ #include #include #include +#include #include #include #include @@ -58,11 +59,6 @@ * - Armada 370 (Globalscale Mirabox): 41us to 43us (Polled) */ #define MVMDIO_SMI_TIMEOUT 1000 /* 1000us = 1ms */ -#define MVMDIO_SMI_POLL_INTERVAL_MIN 45 -#define MVMDIO_SMI_POLL_INTERVAL_MAX 55 - -#define MVMDIO_XSMI_POLL_INTERVAL_MIN 150 -#define MVMDIO_XSMI_POLL_INTERVAL_MAX 160 struct orion_mdio_dev { void __iomem *regs; @@ -84,8 +80,6 @@ enum orion_mdio_bus_type { struct orion_mdio_ops { int (*is_done)(struct orion_mdio_dev *); - unsigned int poll_interval_min; - unsigned int poll_interval_max; }; /* Wait for the SMI unit to be ready for another operation @@ -94,34 +88,23 @@ static int orion_mdio_wait_ready(const struct orion_mdio_ops *ops, struct mii_bus *bus) { struct orion_mdio_dev *dev = bus->priv; - unsigned long timeout = usecs_to_jiffies(MVMDIO_SMI_TIMEOUT); - unsigned long end = jiffies + timeout; - int timedout = 0; + unsigned long timeout; + int done; - while (1) { - if (ops->is_done(dev)) + if (dev->err_interrupt <= 0) { + if (!read_poll_timeout_atomic(ops->is_done, done, done, 2, + MVMDIO_SMI_TIMEOUT, false, dev)) + return 0; + } else { + /* wait_event_timeout does not guarantee a delay of at + * least one whole jiffie, so timeout must be no less + * than two. + */ + timeout = max(usecs_to_jiffies(MVMDIO_SMI_TIMEOUT), 2); + + if (wait_event_timeout(dev->smi_busy_wait, + ops->is_done(dev), timeout)) return 0; - else if (timedout) - break; - - if (dev->err_interrupt <= 0) { - usleep_range(ops->poll_interval_min, - ops->poll_interval_max); - - if (time_is_before_jiffies(end)) - ++timedout; - } else { - /* wait_event_timeout does not guarantee a delay of at - * least one whole jiffie, so timeout must be no less - * than two. - */ - if (timeout < 2) - timeout = 2; - wait_event_timeout(dev->smi_busy_wait, - ops->is_done(dev), timeout); - - ++timedout; - } } dev_err(bus->parent, "Timeout: SMI busy for too long\n"); @@ -135,8 +118,6 @@ static int orion_mdio_smi_is_done(struct orion_mdio_dev *dev) static const struct orion_mdio_ops orion_mdio_smi_ops = { .is_done = orion_mdio_smi_is_done, - .poll_interval_min = MVMDIO_SMI_POLL_INTERVAL_MIN, - .poll_interval_max = MVMDIO_SMI_POLL_INTERVAL_MAX, }; static int orion_mdio_smi_read(struct mii_bus *bus, int mii_id, @@ -200,8 +181,6 @@ static int orion_mdio_xsmi_is_done(struct orion_mdio_dev *dev) static const struct orion_mdio_ops orion_mdio_xsmi_ops = { .is_done = orion_mdio_xsmi_is_done, - .poll_interval_min = MVMDIO_XSMI_POLL_INTERVAL_MIN, - .poll_interval_max = MVMDIO_XSMI_POLL_INTERVAL_MAX, }; static int orion_mdio_xsmi_read(struct mii_bus *bus, int mii_id, -- 2.43.0