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From: "Marek Behún" <kabel@kernel.org>
To: linux-serial@vger.kernel.org,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Pali Rohár" <pali@kernel.org>, "Marek Behún" <kabel@kernel.org>
Subject: [PATCH 5/7] USB: serial: ftdi_sio: Fix baudrate rounding for ASYNC_SPD_CUST
Date: Thu,  7 Jul 2022 16:53:52 +0200	[thread overview]
Message-ID: <20220707145354.29705-6-kabel@kernel.org> (raw)
In-Reply-To: <20220707145354.29705-1-kabel@kernel.org>

From: Pali Rohár <pali@kernel.org>

Use DIV_ROUND_CLOSEST() for more accurate baudrate calculation for
ASYNC_SPD_CUST instead of rounding it just down.

Signed-off-by: Pali Rohár <pali@kernel.org>
Tested-by: Marek Behún <kabel@kernel.org>
---
 drivers/usb/serial/ftdi_sio.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c
index 30744d5779e2..ac84d5779966 100644
--- a/drivers/usb/serial/ftdi_sio.c
+++ b/drivers/usb/serial/ftdi_sio.c
@@ -1317,7 +1317,7 @@ static u32 get_ftdi_divisor(struct tty_struct *tty,
 	if (baud == 38400 &&
 	    ((priv->flags & ASYNC_SPD_MASK) == ASYNC_SPD_CUST) &&
 	     (priv->custom_divisor)) {
-		baud = priv->baud_base / priv->custom_divisor;
+		baud = DIV_ROUND_CLOSEST(priv->baud_base, priv->custom_divisor);
 		dev_dbg(dev, "%s - custom divisor %d sets baud rate to %d\n",
 			__func__, priv->custom_divisor, baud);
 	}
-- 
2.35.1


  parent reply	other threads:[~2022-07-07 14:55 UTC|newest]

Thread overview: 30+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-07-07 14:53 [PATCH 0/7] ftdi_sio driver improvements Marek Behún
2022-07-07 14:53 ` [PATCH 1/7] USB: serial: ftdi_sio: Fix divisor overflow Marek Behún
2022-07-07 15:07   ` Greg Kroah-Hartman
2022-07-07 15:37     ` Marek Behún
2022-07-07 15:50       ` Greg Kroah-Hartman
2022-07-07 14:53 ` [PATCH 2/7] USB: serial: ftdi_sio: Add missing baudrate validation Marek Behún
2022-07-07 15:08   ` Greg Kroah-Hartman
2022-07-07 16:22     ` Marek Behún
2022-07-07 16:50       ` Greg Kroah-Hartman
2022-07-07 14:53 ` [PATCH 3/7] USB: serial: ftdi_sio: Extract SIO divisor code to function Marek Behún
2022-07-07 15:06   ` Greg Kroah-Hartman
2022-07-07 15:41     ` Marek Behún
2022-07-07 15:09   ` Greg Kroah-Hartman
2022-07-07 15:50     ` Marek Behún
2022-07-07 14:53 ` [PATCH 4/7] USB: serial: ftdi_sio: Do not reset baudrate to 9600 on error Marek Behún
2022-07-07 15:10   ` Greg Kroah-Hartman
2022-07-07 15:52     ` Marek Behún
2022-07-07 16:06       ` Greg Kroah-Hartman
2022-07-08 15:51   ` Andy Shevchenko
2022-07-12 11:28     ` m.brock
2022-07-12 12:09       ` Marek Behún
2022-07-12 12:11     ` Marek Behún
2022-07-07 14:53 ` Marek Behún [this message]
2022-07-07 15:11   ` [PATCH 5/7] USB: serial: ftdi_sio: Fix baudrate rounding for ASYNC_SPD_CUST Greg Kroah-Hartman
2022-07-07 16:08     ` Marek Behún
2022-07-07 16:12       ` Greg Kroah-Hartman
2022-07-07 14:53 ` [PATCH 6/7] USB: serial: ftdi_sio: Fix custom_divisor and c_*speed " Marek Behún
2022-07-07 14:53 ` [PATCH 7/7] USB: serial: ftdi_sio: Fill c_*speed fields with real baudrate Marek Behún
2022-07-07 15:11   ` Greg Kroah-Hartman
2022-07-07 15:07 ` [PATCH 0/7] ftdi_sio driver improvements Greg Kroah-Hartman

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