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From: christian pellegrin <chripell@fsfe.org>
To: Feng Tang <feng.tang@intel.com>
Cc: "akpm@linux-foundation.org" <akpm@linux-foundation.org>,
	"greg@kroah.com" <greg@kroah.com>,
	"david-b@pacbell.net" <david-b@pacbell.net>,
	"grant.likely@secretlab.ca" <grant.likely@secretlab.ca>,
	"alan@lxorguk.ukuu.org.uk" <alan@lxorguk.ukuu.org.uk>,
	"spi-devel-general@lists.sourceforge.net" 
	<spi-devel-general@lists.sourceforge.net>,
	"linux-serial@vger.kernel.org" <linux-serial@vger.kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v1 3/4] max3100: adds console support for MAX3100
Date: Thu, 8 Apr 2010 11:31:09 +0200	[thread overview]
Message-ID: <v2ocabda6421004080231r7b7a734ao9fce206a82bf944b@mail.gmail.com> (raw)
In-Reply-To: <20100329104838.49c18075@feng-i7>

On Mon, Mar 29, 2010 at 4:48 AM, Feng Tang <feng.tang@intel.com> wrote:

>> +             tx |= MAX3100_WD | MAX3100_RTS;
>
> Does this imply to have to work with HW flow control? on my platform
> I have to remove the RTS bit to make it work.
>

Finally I had time to check this. If you compare the 8250 (or similar)
data-sheet with the MAX31x0 one you see that the handling of the
RTX/CTS bits is exactly the same (8250 about RTS bit for example:
"When any of these bits are cleared, the associated output is forced
high." and MAX3110: "Request-to-Send Bit. Controls the state of the
RTS output. This bit is reset on power-up (RTS
bit = 0 sets the RTS pin = logic high)."). If you look at the 8250.c
driver (grep for UART_MCR_RTS) you notice that the bit is set on
device open (together with DTR of course). So I think the driver is
doing the right thing here.

-- 
Christian Pellegrin, see http://www.evolware.org/chri/
"Real Programmers don't play tennis, or any other sport which requires
you to change clothes. Mountain climbing is OK, and Real Programmers
wear their climbing boots to work in case a mountain should suddenly
spring up in the middle of the computer room."

WARNING: multiple messages have this Message-ID (diff)
From: christian pellegrin <chripell@fsfe.org>
To: Feng Tang <feng.tang@intel.com>
Cc: "akpm@linux-foundation.org" <akpm@linux-foundation.org>,
	"greg@kroah.com" <greg@kroah.com>,
	"david-b@pacbell.net" <david-b@pacbell.net>,
	"grant.likely@secretlab.ca" <grant.likely@secretlab.ca>,
	"alan@lxorguk.ukuu.org.uk" <alan@lxorguk.ukuu.org.uk>,
	"spi-devel-general@lists.sourceforge.net"
	<spi-devel-general@lists.sourceforge.net>,
	"linux-serial@vger.kernel.org" <linux-serial@vger.kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v1 3/4] max3100: adds console support for MAX3100
Date: Thu, 8 Apr 2010 11:31:09 +0200	[thread overview]
Message-ID: <v2ocabda6421004080231r7b7a734ao9fce206a82bf944b@mail.gmail.com> (raw)
In-Reply-To: <20100329104838.49c18075@feng-i7>

On Mon, Mar 29, 2010 at 4:48 AM, Feng Tang <feng.tang@intel.com> wrote:

>> +             tx |= MAX3100_WD | MAX3100_RTS;
>
> Does this imply to have to work with HW flow control? on my platform
> I have to remove the RTS bit to make it work.
>

Finally I had time to check this. If you compare the 8250 (or similar)
data-sheet with the MAX31x0 one you see that the handling of the
RTX/CTS bits is exactly the same (8250 about RTS bit for example:
"When any of these bits are cleared, the associated output is forced
high." and MAX3110: "Request-to-Send Bit. Controls the state of the
RTS output. This bit is reset on power-up (RTS
bit = 0 sets the RTS pin = logic high)."). If you look at the 8250.c
driver (grep for UART_MCR_RTS) you notice that the bit is set on
device open (together with DTR of course). So I think the driver is
doing the right thing here.

-- 
Christian Pellegrin, see http://www.evolware.org/chri/
"Real Programmers don't play tennis, or any other sport which requires
you to change clothes. Mountain climbing is OK, and Real Programmers
wear their climbing boots to work in case a mountain should suddenly
spring up in the middle of the computer room."
--
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the body of a message to majordomo@vger.kernel.org
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  parent reply	other threads:[~2010-04-08  9:31 UTC|newest]

Thread overview: 39+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-03-23 10:29 [PATCH v1 0/3] max3100: improvements christian pellegrin
2010-03-23 10:28 ` [PATCH v1 1/4] max3100: added raise_threaded_irq Christian Pellegrin
2010-03-23 10:28   ` Christian Pellegrin
2010-03-23 10:28   ` Christian Pellegrin
2010-03-23 10:29   ` [PATCH v1 2/4] max3100: moved to threaded interrupt Christian Pellegrin
2010-03-23 10:29     ` Christian Pellegrin
2010-03-23 10:29     ` Christian Pellegrin
2010-03-23 10:29   ` [PATCH v1 3/4] max3100: adds console support for MAX3100 Christian Pellegrin
2010-03-23 10:29     ` Christian Pellegrin
2010-03-23 10:29     ` Christian Pellegrin
2010-03-29  2:48     ` Feng Tang
2010-03-29  2:48       ` Feng Tang
2010-03-29  2:48       ` Feng Tang
2010-03-29  6:11       ` christian pellegrin
2010-03-29  6:11         ` christian pellegrin
2010-03-29  7:06         ` Feng Tang
2010-03-29  7:06           ` Feng Tang
2010-03-29 12:55           ` christian pellegrin
2010-03-29 12:55             ` christian pellegrin
2010-03-30  2:14             ` Feng Tang
2010-03-30  6:49               ` christian pellegrin
2010-03-30  7:19                 ` Feng Tang
2010-03-30  8:00                   ` christian pellegrin
2010-03-30  8:46                 ` Alan Cox
2010-03-30 12:03                   ` christian pellegrin
2010-03-31  6:04                     ` Grant Likely
2010-04-05 18:19                       ` christian pellegrin
2010-04-05 19:00                         ` Grant Likely
2010-04-08  9:31       ` christian pellegrin [this message]
2010-04-08  9:31         ` christian pellegrin
2010-04-08  9:43         ` christian pellegrin
2010-04-08  9:43           ` christian pellegrin
2010-03-23 10:29   ` [PATCH v1 4/4] max3100: introduced to_max3100_port, small style fixes Christian Pellegrin
2010-03-23 10:29     ` Christian Pellegrin
2010-03-23 10:29     ` Christian Pellegrin
2010-04-15 23:22   ` [PATCH v1 1/4] max3100: added raise_threaded_irq Thomas Gleixner
2010-04-16 16:18     ` christian pellegrin
2010-04-16 22:06       ` Thomas Gleixner
2010-04-17 16:25         ` christian pellegrin

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