From 7e12a6fcbf266eb0d5b19761f91b2964ad18e371 Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Fri, 1 Nov 2013 09:19:34 -0700 Subject: [PATCH] Revert "usb: pl2303: do not round to the next nearest standard baud rate for the divisor based baud rate encoding method" MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit This reverts commit 75417d9f99f89ab241de69d7db15af5842b488c4. Revert all of the pl2303 changes that went into 3.12-rc1 and -rc2 as they cause regressions on some versions of the chip. This will all be revisited for later kernel versions when we can figure out how to handle this in a way that does not break working devices. Reported-by: Mika Westerberg Cc: Frank Schäfer Acked-by: Johan Hovold Signed-off-by: Greg Kroah-Hartman --- drivers/usb/serial/pl2303.c | 65 ++++++++++++++++--------------------- 1 file changed, 28 insertions(+), 37 deletions(-) diff --git a/drivers/usb/serial/pl2303.c b/drivers/usb/serial/pl2303.c index 04390dff926a..b93b3b30dec5 100644 --- a/drivers/usb/serial/pl2303.c +++ b/drivers/usb/serial/pl2303.c @@ -273,46 +273,44 @@ static void pl2303_encode_baudrate(struct tty_struct *tty, struct usb_serial_port *port, u8 buf[4]) { + const int baud_sup[] = { 75, 150, 300, 600, 1200, 1800, 2400, 3600, + 4800, 7200, 9600, 14400, 19200, 28800, 38400, + 57600, 115200, 230400, 460800, 500000, 614400, + 921600, 1228800, 2457600, 3000000, 6000000 }; + struct usb_serial *serial = port->serial; struct pl2303_serial_private *spriv = usb_get_serial_data(serial); int baud; + int i; + /* + * NOTE: Only the values defined in baud_sup are supported! + * => if unsupported values are set, the PL2303 seems to use + * 9600 baud (at least my PL2303X always does) + */ baud = tty_get_baud_rate(tty); dev_dbg(&port->dev, "baud requested = %d\n", baud); if (!baud) return; - if (spriv->type != HX || baud <= 115200) { - /* - * NOTE: Only the values defined in baud_sup are supported ! - * => if unsupported values are set, the PL2303 seems to - * use 9600 baud (at least my PL2303X always does) - */ - const int baud_sup[] = { 75, 150, 300, 600, 1200, 1800, 2400, - 3600, 4800, 7200, 9600, 14400, 19200, - 28800, 38400, 57600, 115200, 230400, - 460800, 500000, 614400, 921600, - 1228800, 2457600, 3000000, 6000000 }; - int i; - - /* Set baudrate to nearest supported value */ - for (i = 0; i < ARRAY_SIZE(baud_sup); ++i) { - if (baud_sup[i] > baud) - break; - } + /* Set baudrate to nearest supported value */ + for (i = 0; i < ARRAY_SIZE(baud_sup); ++i) { + if (baud_sup[i] > baud) + break; + } - if (i == ARRAY_SIZE(baud_sup)) - baud = baud_sup[i - 1]; - else if (i > 0 - && (baud_sup[i] - baud) > (baud - baud_sup[i - 1])) - baud = baud_sup[i - 1]; - else - baud = baud_sup[i]; + if (i == ARRAY_SIZE(baud_sup)) + baud = baud_sup[i - 1]; + else if (i > 0 && (baud_sup[i] - baud) > (baud - baud_sup[i - 1])) + baud = baud_sup[i - 1]; + else + baud = baud_sup[i]; - /* type_0, type_1 only support up to 1228800 baud */ - if (spriv->type != HX) - baud = min_t(int, baud, 1228800); + /* type_0, type_1 only support up to 1228800 baud */ + if (spriv->type != HX) + baud = min_t(int, baud, 1228800); + if (spriv->type != HX || baud <= 115200) { /* Direct (standard) baud rate encoding method */ put_unaligned_le32(baud, buf); } else { @@ -333,17 +331,10 @@ static void pl2303_encode_baudrate(struct tty_struct *tty, * => 8 < B < 16: device seems to work not properly * => B <= 8: device uses the max. value B = 512 instead */ - unsigned int A, B; - /* Respect the specified baud rate limits */ - baud = max_t(int, baud, 75); - if (spriv->type == HX) - baud = min_t(int, baud, 6000000); - else - baud = min_t(int, baud, 1228800); /* Determine factors A and B */ - A = 0; - B = 12000000 * 32 / baud; /* 12MHz */ + unsigned int A = 0; + unsigned int B = 12000000 * 32 / baud; /* 12MHz */ B <<= 1; /* Add one bit for rounding */ while (B > (512 << 1) && A <= 14) { A += 2; -- 2.30.2