From: Sergey Organov <sorganov@gmail.com>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-serial@vger.kernel.org,
"Fabio Estevam" <festevam@gmail.com>,
"Jiri Slaby" <jirislaby@kernel.org>,
"Richard Genoud" <richard.genoud@gmail.com>,
"Sascha Hauer" <s.hauer@pengutronix.de>,
"Shawn Guo" <shawnguo@kernel.org>,
"Tim Harvey" <tharvey@gateworks.com>,
"Tomasz Moń" <tomasz.mon@camlingroup.com>,
"Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>,
"Johan Hovold" <johan@kernel.org>,
"Ilpo Järvinen" <ilpo.jarvinen@linux.intel.com>,
"Sherry Sun" <sherry.sun@nxp.com>,
"Stefan Wahren" <stefan.wahren@i2se.com>,
linux-arm-kernel@lists.infradead.org,
"NXP Linux Team" <linux-imx@nxp.com>,
"Pengutronix Kernel Team" <kernel@pengutronix.de>,
"Sergey Organov" <sorganov@gmail.com>
Subject: [PATCH RESEND] serial: imx: get rid of registers shadowing
Date: Wed, 1 Feb 2023 17:16:03 +0300 [thread overview]
Message-ID: <20230201141603.4205-1-sorganov@gmail.com> (raw)
In-Reply-To: <87bko4e65y.fsf@osv.gnss.ru>
Neither registers shadowing is functionally needed as all the registers are
read-write, nor the shadowing makes much sense for speed-up, as most speed
critical reads/writes (of data Rx/Tx registers) are not shadowed anyway.
Moreover, the shadowing code is obviously pure overhead on the write path.
Get rid of the shadowing code and variables due to above considerations.
Signed-off-by: Sergey Organov <sorganov@gmail.com>
---
NOTE: This patch is extracted from patch series "[PATCH 0/8] serial: imx:
work-around for hardware RX flood, and then isr improvements" due to
objection of Uwe Kleine-König <u.kleine-koenig@pengutronix.de>. I still
believe this is an improvement, so I re-submit the patch separately.
drivers/tty/serial/imx.c | 65 ++--------------------------------------
1 file changed, 3 insertions(+), 62 deletions(-)
diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
index 757825edb0cd..f4e2db21d0fe 100644
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -210,13 +210,6 @@ struct imx_port {
struct mctrl_gpios *gpios;
- /* shadow registers */
- unsigned int ucr1;
- unsigned int ucr2;
- unsigned int ucr3;
- unsigned int ucr4;
- unsigned int ufcr;
-
/* DMA fields */
unsigned int dma_is_enabled:1;
unsigned int dma_is_rxing:1;
@@ -273,59 +266,14 @@ static const struct of_device_id imx_uart_dt_ids[] = {
};
MODULE_DEVICE_TABLE(of, imx_uart_dt_ids);
-static void imx_uart_writel(struct imx_port *sport, u32 val, u32 offset)
+static inline void imx_uart_writel(struct imx_port *sport, u32 val, u32 offset)
{
- switch (offset) {
- case UCR1:
- sport->ucr1 = val;
- break;
- case UCR2:
- sport->ucr2 = val;
- break;
- case UCR3:
- sport->ucr3 = val;
- break;
- case UCR4:
- sport->ucr4 = val;
- break;
- case UFCR:
- sport->ufcr = val;
- break;
- default:
- break;
- }
writel(val, sport->port.membase + offset);
}
-static u32 imx_uart_readl(struct imx_port *sport, u32 offset)
+static inline u32 imx_uart_readl(struct imx_port *sport, u32 offset)
{
- switch (offset) {
- case UCR1:
- return sport->ucr1;
- break;
- case UCR2:
- /*
- * UCR2_SRST is the only bit in the cached registers that might
- * differ from the value that was last written. As it only
- * automatically becomes one after being cleared, reread
- * conditionally.
- */
- if (!(sport->ucr2 & UCR2_SRST))
- sport->ucr2 = readl(sport->port.membase + offset);
- return sport->ucr2;
- break;
- case UCR3:
- return sport->ucr3;
- break;
- case UCR4:
- return sport->ucr4;
- break;
- case UFCR:
- return sport->ufcr;
- break;
- default:
- return readl(sport->port.membase + offset);
- }
+ return readl(sport->port.membase + offset);
}
static inline unsigned imx_uart_uts_reg(struct imx_port *sport)
@@ -2340,13 +2288,6 @@ static int imx_uart_probe(struct platform_device *pdev)
return ret;
}
- /* initialize shadow register values */
- sport->ucr1 = readl(sport->port.membase + UCR1);
- sport->ucr2 = readl(sport->port.membase + UCR2);
- sport->ucr3 = readl(sport->port.membase + UCR3);
- sport->ucr4 = readl(sport->port.membase + UCR4);
- sport->ufcr = readl(sport->port.membase + UFCR);
-
ret = uart_get_rs485_mode(&sport->port);
if (ret) {
clk_disable_unprepare(sport->clk_ipg);
base-commit: 40c18f363a0806d4f566e8a9a9bd2d7766a72cf5
--
2.30.1
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next prev parent reply other threads:[~2023-02-01 14:34 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <87bko4e65y.fsf@osv.gnss.ru>
2023-01-13 18:43 ` [PATCH 0/8] serial: imx: work-around for hardware RX flood, and then isr improvements Sergey Organov
2023-01-13 18:43 ` [PATCH 1/8] serial: imx: factor-out common code to imx_uart_soft_reset() Sergey Organov
2023-01-16 10:30 ` Ilpo Järvinen
2023-01-17 13:42 ` Sergey Organov
2023-01-13 18:43 ` [PATCH 2/8] serial: imx: work-around for hardware RX flood Sergey Organov
2023-01-13 18:43 ` [PATCH 3/8] serial: imx: do not sysrq broken chars Sergey Organov
2023-01-16 10:41 ` Ilpo Järvinen
2023-01-16 15:24 ` Johan Hovold
2023-01-17 17:35 ` Sergey Organov
2023-01-18 8:06 ` Johan Hovold
2023-01-13 18:43 ` [PATCH 4/8] serial: imx: do not break from FIFO reading loop prematurely Sergey Organov
2023-01-13 18:43 ` [PATCH 5/8] serial: imx: remove redundant USR2 read from FIFO reading loop Sergey Organov
2023-01-16 10:50 ` Ilpo Järvinen
2023-01-13 18:43 ` [PATCH 6/8] serial: imx: stop using USR2 in " Sergey Organov
2023-01-16 10:54 ` Ilpo Järvinen
2023-01-17 13:30 ` Sergey Organov
2023-01-13 18:43 ` [PATCH 7/8] serial: imx: use readl() to optimize " Sergey Organov
2023-01-16 11:03 ` Ilpo Järvinen
2023-01-17 17:43 ` Sergey Organov
2023-01-18 8:24 ` Ilpo Järvinen
2023-01-18 15:43 ` Sergey Organov
2023-01-18 19:29 ` Ilpo Järvinen
2023-01-17 10:20 ` Sherry Sun
2023-01-17 17:48 ` Sergey Organov
2023-01-17 11:32 ` Uwe Kleine-König
2023-01-17 13:22 ` Sergey Organov
2023-01-17 21:27 ` Uwe Kleine-König
2023-01-18 15:40 ` Sergey Organov
2023-01-19 7:01 ` Uwe Kleine-König
2023-01-21 18:04 ` Sergey Organov
2023-01-13 18:43 ` [PATCH 8/8] serial: imx: refine local variables in rxint() Sergey Organov
2023-01-21 15:36 ` [PATCH v1 0/7] serial: imx: work-around for hardware RX flood, and then isr improvements Sergey Organov
2023-01-21 15:36 ` [PATCH v1 1/7] serial: imx: factor-out common code to imx_uart_soft_reset() Sergey Organov
2023-01-21 15:36 ` [PATCH v1 2/7] serial: imx: work-around for hardware RX flood Sergey Organov
2023-01-21 15:36 ` [PATCH v1 3/7] serial: imx: do not sysrq broken chars Sergey Organov
2023-01-21 16:12 ` Stefan Wahren
2023-01-21 21:04 ` Sergey Organov
2023-01-23 12:38 ` Ilpo Järvinen
2023-01-23 16:34 ` Sergey Organov
2023-01-21 15:36 ` [PATCH v1 4/7] serial: imx: do not break from FIFO reading loop prematurely Sergey Organov
2023-01-21 15:36 ` [PATCH v1 5/7] serial: imx: remove redundant USR2 read from FIFO reading loop Sergey Organov
2023-01-21 15:36 ` [PATCH v1 6/7] serial: imx: stop using USR2 in " Sergey Organov
2023-01-21 15:36 ` [PATCH v1 7/7] serial: imx: refine local variables in rxint() Sergey Organov
2023-02-01 14:16 ` Sergey Organov [this message]
2023-02-01 14:26 ` [PATCH v1 RESEND 0/7] serial: imx: work-around for hardware RX flood, and then isr improvements Sergey Organov
2023-02-01 14:26 ` [PATCH v1 1/7] serial: imx: factor-out common code to imx_uart_soft_reset() Sergey Organov
2023-02-01 14:26 ` [PATCH v1 2/7] serial: imx: work-around for hardware RX flood Sergey Organov
2023-02-01 14:26 ` [PATCH v1 3/7] serial: imx: do not sysrq broken chars Sergey Organov
2023-02-01 14:26 ` [PATCH v1 4/7] serial: imx: do not break from FIFO reading loop prematurely Sergey Organov
2023-02-01 14:26 ` [PATCH v1 5/7] serial: imx: remove redundant USR2 read from FIFO reading loop Sergey Organov
2023-02-01 14:26 ` [PATCH v1 6/7] serial: imx: stop using USR2 in " Sergey Organov
2023-02-01 14:27 ` [PATCH v1 7/7] serial: imx: refine local variables in rxint() Sergey Organov
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