From: Feng Tang <feng.tang@intel.com>
To: Christian Pellegrin <chripell@fsfe.org>
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>,
Christian Pellegrin <chripell@fsfe.org>
Subject: Re: [PATCH v1 3/4] max3100: adds console support for MAX3100
Date: Mon, 29 Mar 2010 10:48:38 +0800 [thread overview]
Message-ID: <20100329104838.49c18075@feng-i7> (raw)
In-Reply-To: <1269340170-6558-1-git-send-email-chripell@fsfe.org>
Hi,
I modified the code a little and run it on our HW platform, it really show
some sigh of life: it can boots to console (the print format is not so good),
I can input command and it execute correctly, but very slow, I type 3
characters and it takes about 2 seconds to echo back on screen and start the
execution, and after about 1 minute, the console hang there and input stopped
to work.
I also have some comments inline.
Thanks,
Feng
On Tue, 23 Mar 2010 18:29:30 +0800
Christian Pellegrin <chripell@fsfe.org> wrote:
> This patch adds console support for the MAX3100 UART
> (console=ttyMAX0,11500). The SPI subsystem and an
115200?
>
> +#ifdef CONFIG_SERIAL_MAX3100_CONSOLE
> +
> +static void max3100_console_work(struct work_struct *w)
> +{
> + struct max3100_port *s = container_of(w, struct max3100_port,
> + console_work);
> + unsigned long start;
> + u16 tx, rx;
> +
> + while (s->console_head != s->console_tail &&
> + (s->console_flags & MAX3100_SUSPENDING) == 0) {
> + start = jiffies;
> + do {
> + tx = MAX3100_RC;
> + max3100_sr(s, tx, &rx);
> + } while ((rx & MAX3100_T) == 0 &&
> + !time_after(jiffies, start +
> s->console_tout));
> + tx = s->console_buf[s->console_tail];
> + max3100_calc_parity(s, &tx);
> + 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.
> + max3100_sr(s, tx, &rx);
It doesn't handle received characters here? If the console is printing out
a bulk of message while user input some command, the command may be ignored.
Myself have met the same problem in our driver.
> + s->console_tail = (s->console_tail + 1) %
> CONSOLE_BUF_SIZE;
> + }
> +}
> +
> +static void max3100_console_putchar(struct uart_port *port, int ch)
> +{
> + struct max3100_port *s = to_max3100_port(port);
> + int next = (s->console_head + 1) % CONSOLE_BUF_SIZE;
> +
> + if (next != s->console_tail) {
> + s->console_buf[next] = ch;
> + s->console_head = next;
> + }
Also I saw max3100_sr() uses cpu_to_be16() and be16_to_cpu(), is it really
necessary, our platform is little-endian(x86), and I have to disable them
to make the code work. Is your test platform big-endian?
next prev parent reply other threads:[~2010-03-29 2:44 UTC|newest]
Thread overview: 15+ 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 10:29 ` [PATCH v1 2/4] max3100: moved to threaded interrupt Christian Pellegrin
2010-03-23 10:29 ` [PATCH v1 3/4] max3100: adds console support for MAX3100 Christian Pellegrin
2010-03-29 2:48 ` Feng Tang [this message]
2010-03-29 6:11 ` christian pellegrin
2010-03-29 7:06 ` Feng Tang
2010-03-29 12:55 ` christian pellegrin
2010-04-08 9:31 ` 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
2010-04-15 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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