Hello,
the recent addition of the FT232H showed that baudrate was set wrong. See
gmane.linux.usb.general: "[ftdi_sio] FT232H support". With the old code,
the MSB of the 4 encoded fractional divider bits and more important the
clock predivider bits got lost. Adding the FT232H to the code patch were
these bits are shifted solves the problem. I verified baud rates with a
scope now.
I suspect, that the BM device probably needs these bits shifted too. But
there is no predivider bit, so this is not obvious, and a missing MSB of the
encoded fractional divider only shifts the resulting baudrate minimal.
The AM has only 3 bits of encoded fractional divider, so it is not impacted.
I have no BM device to test, so I only added a comment and left the code for
the BM untouched.
This time with checkpatch happy.
Bye
--
Uwe Bonnes bon@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Institut fuer Kernphysik Schlossgartenstrasse 9 64289 Darmstadt
--------- Tel. 06151 162516 -------- Fax. 06151 164321 ----------
>From 892f1ac2b0b47ffc7adf70ecbe5d7d2f31c79232 Mon Sep 17 00:00:00 2001
From: Uwe Bonnes <bon@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx>
Date: Tue, 12 Jul 2011 18:47:08 +0200
Subject: ftdi_sio: For the FT232H FTDI_SIO_SET_BAUDRATE_REQUEST, index needs to be shifted too
---
drivers/usb/serial/ftdi_sio.c | 5 ++++-
1 files changed, 4 insertions(+), 1 deletions(-)
diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c
index 2e06b90..0692a36 100644
--- a/drivers/usb/serial/ftdi_sio.c
+++ b/drivers/usb/serial/ftdi_sio.c
@@ -1205,7 +1205,10 @@ static int change_speed(struct tty_struct *tty, struct usb_serial_port *port)
urb_index_value = get_ftdi_divisor(tty, port);
urb_value = (__u16)urb_index_value;
urb_index = (__u16)(urb_index_value >> 16);
- if (priv->interface) { /* FT2232C */
+ if ((priv->chip_type == FT2232C) || (priv->chip_type == FT2232H) ||
+ (priv->chip_type == FT4232H) || (priv->chip_type == FT232H)) {
+ /* Probably the BM type needs the MSB of the encoded fractional
+ * divider also moved like for the chips above. Any infos? */
urb_index = (__u16)((urb_index << 8) | priv->interface);
}
--
1.7.3.4
Signed-off-by: Uwe Bonnes <bon@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx>
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