From: Johannes Weiner <hannes-kernel@saeurebad.de>
To: Andre Haupt <andre@bitwigglers.org>
Cc: kernel-janitors@vger.kernel.org, linux-serial@vger.kernel.org,
linux-kernel@vger.kernel.org, trivial@kernel.org
Subject: Re: [PATCH][KJ] 8250: remove unnecessary variable tmout from wait_for_xmitr()
Date: Thu, 13 Dec 2007 14:51:54 +0000 [thread overview]
Message-ID: <x7hcim4ph1.fsf@saeurebad.de> (raw)
In-Reply-To: <11975548843528-git-send-email-andre@bitwigglers.org> (Andre Haupt's message of "Thu, 13 Dec 2007 15:08:04 +0100")
Hi,
Andre Haupt <andre@bitwigglers.org> writes:
> This fixes a sparse warning about symbol tmout shadowing an earlier one.
>
> Signed-off-by: Andre Haupt <andre@bitwigglers.org>
> ---
> drivers/serial/8250.c | 1 -
> 1 files changed, 0 insertions(+), 1 deletions(-)
The whole timeout loops look somewhat odd. How about the following,
totally untested, solution?
This converts the function to use more common timeout-loop constructs,
gets rid of the shadowed variable and localises another variable even
more! Hooray!
Hannes
Signed-off-by: Johannes Weiner <hannes@saeurebad.de>
---
drivers/serial/8250.c | 18 +++++++++---------
1 files changed, 9 insertions(+), 9 deletions(-)
diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c
index f94109c..7215f6a 100644
--- a/drivers/serial/8250.c
+++ b/drivers/serial/8250.c
@@ -1712,30 +1712,30 @@ static void serial8250_break_ctl(struct uart_port *port, int break_state)
*/
static inline void wait_for_xmitr(struct uart_8250_port *up, int bits)
{
- unsigned int status, tmout = 10000;
+ unsigned int tmout;
/* Wait up to 10ms for the character(s) to be sent. */
+ tmout = jiffies + jiffies_to_msecs(10);
do {
- status = serial_in(up, UART_LSR);
+ unsigned int status = serial_in(up, UART_LSR);
- up->lsr_saved_flags |= status & LSR_SAVE_FLAGS;
-
- if (--tmout = 0)
+ up->lsr_saved_flags |= (status & LSR_SAVE_FLAGS);
+ if ((status & bits) = bits)
break;
udelay(1);
- } while ((status & bits) != bits);
+ } while (time_after_eq(tmout, jiffies));
/* Wait up to 1s for flow control if necessary */
if (up->port.flags & UPF_CONS_FLOW) {
- unsigned int tmout;
- for (tmout = 1000000; tmout; tmout--) {
+ tmout = jiffies + jiffies_to_msecs(1000);
+ do {
unsigned int msr = serial_in(up, UART_MSR);
up->msr_saved_flags |= msr & MSR_SAVE_FLAGS;
if (msr & UART_MSR_CTS)
break;
udelay(1);
touch_nmi_watchdog();
- }
+ } while (time_after_eq(tmout, jiffies));
}
}
WARNING: multiple messages have this Message-ID (diff)
From: Johannes Weiner <hannes-kernel@saeurebad.de>
To: Andre Haupt <andre@bitwigglers.org>
Cc: kernel-janitors@vger.kernel.org, linux-serial@vger.kernel.org,
linux-kernel@vger.kernel.org, trivial@kernel.org
Subject: Re: [PATCH][KJ] 8250: remove unnecessary variable tmout from wait_for_xmitr()
Date: Thu, 13 Dec 2007 15:51:54 +0100 [thread overview]
Message-ID: <x7hcim4ph1.fsf@saeurebad.de> (raw)
In-Reply-To: <11975548843528-git-send-email-andre@bitwigglers.org> (Andre Haupt's message of "Thu, 13 Dec 2007 15:08:04 +0100")
Hi,
Andre Haupt <andre@bitwigglers.org> writes:
> This fixes a sparse warning about symbol tmout shadowing an earlier one.
>
> Signed-off-by: Andre Haupt <andre@bitwigglers.org>
> ---
> drivers/serial/8250.c | 1 -
> 1 files changed, 0 insertions(+), 1 deletions(-)
The whole timeout loops look somewhat odd. How about the following,
totally untested, solution?
This converts the function to use more common timeout-loop constructs,
gets rid of the shadowed variable and localises another variable even
more! Hooray!
Hannes
Signed-off-by: Johannes Weiner <hannes@saeurebad.de>
---
drivers/serial/8250.c | 18 +++++++++---------
1 files changed, 9 insertions(+), 9 deletions(-)
diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c
index f94109c..7215f6a 100644
--- a/drivers/serial/8250.c
+++ b/drivers/serial/8250.c
@@ -1712,30 +1712,30 @@ static void serial8250_break_ctl(struct uart_port *port, int break_state)
*/
static inline void wait_for_xmitr(struct uart_8250_port *up, int bits)
{
- unsigned int status, tmout = 10000;
+ unsigned int tmout;
/* Wait up to 10ms for the character(s) to be sent. */
+ tmout = jiffies + jiffies_to_msecs(10);
do {
- status = serial_in(up, UART_LSR);
+ unsigned int status = serial_in(up, UART_LSR);
- up->lsr_saved_flags |= status & LSR_SAVE_FLAGS;
-
- if (--tmout == 0)
+ up->lsr_saved_flags |= (status & LSR_SAVE_FLAGS);
+ if ((status & bits) == bits)
break;
udelay(1);
- } while ((status & bits) != bits);
+ } while (time_after_eq(tmout, jiffies));
/* Wait up to 1s for flow control if necessary */
if (up->port.flags & UPF_CONS_FLOW) {
- unsigned int tmout;
- for (tmout = 1000000; tmout; tmout--) {
+ tmout = jiffies + jiffies_to_msecs(1000);
+ do {
unsigned int msr = serial_in(up, UART_MSR);
up->msr_saved_flags |= msr & MSR_SAVE_FLAGS;
if (msr & UART_MSR_CTS)
break;
udelay(1);
touch_nmi_watchdog();
- }
+ } while (time_after_eq(tmout, jiffies));
}
}
next prev parent reply other threads:[~2007-12-13 14:51 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-12-13 14:08 [PATCH][KJ] 8250: remove unnecessary variable tmout from wait_for_xmitr() Andre Haupt
2007-12-13 14:08 ` Andre Haupt
2007-12-13 14:51 ` Johannes Weiner [this message]
2007-12-13 14:51 ` Johannes Weiner
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