* [PATCH] i2c: Make sure i2c_algo_bit_data.timeout is HZ-independent
@ 2009-02-22 11:50 Jean Delvare
[not found] ` <20090222125005.75b2d661-ig7AzVSIIG7kN2dkZ6Wm7A@public.gmane.org>
0 siblings, 1 reply; 5+ messages in thread
From: Jean Delvare @ 2009-02-22 11:50 UTC (permalink / raw)
To: Linux I2C; +Cc: Russell King, Lennert Buytenhek, Len Sorensen
i2c_algo_bit_data.timeout is supposed to be in jiffies, so drivers
should use set this value in terms of HZ.
Ultimately I think this field should be discarded in favor of
i2c_adapter.timeout, but that's left for a future patch.
Signed-off-by: Jean Delvare <khali-PUYAD+kWke1g9hUCZPvPmw@public.gmane.org>
Cc: Russell King <rmk+kernel-lFZ/pmaqli7XmaaqVzeoHQ@public.gmane.org>
Cc: Lennert Buytenhek <kernel-OLH4Qvv75CYX/NnBR394Jw@public.gmane.org>
Cc: Len Sorensen <lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys@public.gmane.org>
---
drivers/i2c/busses/i2c-acorn.c | 2 +-
drivers/i2c/busses/i2c-ixp2000.c | 2 +-
drivers/i2c/busses/scx200_i2c.c | 2 +-
3 files changed, 3 insertions(+), 3 deletions(-)
--- linux-2.6.29-rc5.orig/drivers/i2c/busses/scx200_i2c.c 2009-02-22 12:32:33.000000000 +0100
+++ linux-2.6.29-rc5/drivers/i2c/busses/scx200_i2c.c 2009-02-22 12:32:45.000000000 +0100
@@ -76,7 +76,7 @@ static struct i2c_algo_bit_data scx200_i
.getsda = scx200_i2c_getsda,
.getscl = scx200_i2c_getscl,
.udelay = 10,
- .timeout = 100,
+ .timeout = HZ,
};
static struct i2c_adapter scx200_i2c_ops = {
--- linux-2.6.29-rc5.orig/drivers/i2c/busses/i2c-acorn.c 2009-02-22 12:32:33.000000000 +0100
+++ linux-2.6.29-rc5/drivers/i2c/busses/i2c-acorn.c 2009-02-22 12:32:45.000000000 +0100
@@ -79,7 +79,7 @@ static struct i2c_algo_bit_data ioc_data
.getsda = ioc_getsda,
.getscl = ioc_getscl,
.udelay = 80,
- .timeout = 100
+ .timeout = HZ,
};
static struct i2c_adapter ioc_ops = {
--- linux-2.6.29-rc5.orig/drivers/i2c/busses/i2c-ixp2000.c 2009-02-22 12:32:33.000000000 +0100
+++ linux-2.6.29-rc5/drivers/i2c/busses/i2c-ixp2000.c 2009-02-22 12:32:45.000000000 +0100
@@ -114,7 +114,7 @@ static int ixp2000_i2c_probe(struct plat
drv_data->algo_data.getsda = ixp2000_bit_getsda;
drv_data->algo_data.getscl = ixp2000_bit_getscl;
drv_data->algo_data.udelay = 6;
- drv_data->algo_data.timeout = 100;
+ drv_data->algo_data.timeout = HZ;
strlcpy(drv_data->adapter.name, plat_dev->dev.driver->name,
sizeof(drv_data->adapter.name));
--
Jean Delvare
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] i2c: Make sure i2c_algo_bit_data.timeout is HZ-independent
[not found] ` <20090222125005.75b2d661-ig7AzVSIIG7kN2dkZ6Wm7A@public.gmane.org>
@ 2009-02-22 11:52 ` Lennert Buytenhek
2009-02-22 12:03 ` Russell King
2009-02-23 15:00 ` Lennart Sorensen
2 siblings, 0 replies; 5+ messages in thread
From: Lennert Buytenhek @ 2009-02-22 11:52 UTC (permalink / raw)
To: Jean Delvare; +Cc: Linux I2C, Russell King, Len Sorensen
On Sun, Feb 22, 2009 at 12:50:05PM +0100, Jean Delvare wrote:
> i2c_algo_bit_data.timeout is supposed to be in jiffies, so drivers
> should use set this value in terms of HZ.
>
> Ultimately I think this field should be discarded in favor of
> i2c_adapter.timeout, but that's left for a future patch.
>
> Signed-off-by: Jean Delvare <khali-PUYAD+kWke1g9hUCZPvPmw@public.gmane.org>
> Cc: Russell King <rmk+kernel-lFZ/pmaqli7XmaaqVzeoHQ@public.gmane.org>
> Cc: Lennert Buytenhek <kernel-OLH4Qvv75CYX/NnBR394Jw@public.gmane.org>
> Cc: Len Sorensen <lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys@public.gmane.org>
> ---
> drivers/i2c/busses/i2c-acorn.c | 2 +-
> drivers/i2c/busses/i2c-ixp2000.c | 2 +-
> drivers/i2c/busses/scx200_i2c.c | 2 +-
> 3 files changed, 3 insertions(+), 3 deletions(-)
For the drivers/i2c/busses/i2c-ixp2000.c part:
Acked-by: Lennert Buytenhek <kernel-OLH4Qvv75CYX/NnBR394Jw@public.gmane.org>
Thanks.
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] i2c: Make sure i2c_algo_bit_data.timeout is HZ-independent
[not found] ` <20090222125005.75b2d661-ig7AzVSIIG7kN2dkZ6Wm7A@public.gmane.org>
2009-02-22 11:52 ` Lennert Buytenhek
@ 2009-02-22 12:03 ` Russell King
2009-02-23 15:00 ` Lennart Sorensen
2 siblings, 0 replies; 5+ messages in thread
From: Russell King @ 2009-02-22 12:03 UTC (permalink / raw)
To: Jean Delvare; +Cc: Linux I2C, Lennert Buytenhek, Len Sorensen
On Sun, Feb 22, 2009 at 12:50:05PM +0100, Jean Delvare wrote:
> i2c_algo_bit_data.timeout is supposed to be in jiffies, so drivers
> should use set this value in terms of HZ.
>
> Ultimately I think this field should be discarded in favor of
> i2c_adapter.timeout, but that's left for a future patch.
>
> Signed-off-by: Jean Delvare <khali-PUYAD+kWke1g9hUCZPvPmw@public.gmane.org>
Thanks.
Acked-by: Russell King <rmk+kernel-lFZ/pmaqli7XmaaqVzeoHQ@public.gmane.org>
> Cc: Lennert Buytenhek <kernel-OLH4Qvv75CYX/NnBR394Jw@public.gmane.org>
> Cc: Len Sorensen <lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys@public.gmane.org>
> ---
> drivers/i2c/busses/i2c-acorn.c | 2 +-
> drivers/i2c/busses/i2c-ixp2000.c | 2 +-
> drivers/i2c/busses/scx200_i2c.c | 2 +-
> 3 files changed, 3 insertions(+), 3 deletions(-)
>
> --- linux-2.6.29-rc5.orig/drivers/i2c/busses/scx200_i2c.c 2009-02-22 12:32:33.000000000 +0100
> +++ linux-2.6.29-rc5/drivers/i2c/busses/scx200_i2c.c 2009-02-22 12:32:45.000000000 +0100
> @@ -76,7 +76,7 @@ static struct i2c_algo_bit_data scx200_i
> .getsda = scx200_i2c_getsda,
> .getscl = scx200_i2c_getscl,
> .udelay = 10,
> - .timeout = 100,
> + .timeout = HZ,
> };
>
> static struct i2c_adapter scx200_i2c_ops = {
> --- linux-2.6.29-rc5.orig/drivers/i2c/busses/i2c-acorn.c 2009-02-22 12:32:33.000000000 +0100
> +++ linux-2.6.29-rc5/drivers/i2c/busses/i2c-acorn.c 2009-02-22 12:32:45.000000000 +0100
> @@ -79,7 +79,7 @@ static struct i2c_algo_bit_data ioc_data
> .getsda = ioc_getsda,
> .getscl = ioc_getscl,
> .udelay = 80,
> - .timeout = 100
> + .timeout = HZ,
> };
>
> static struct i2c_adapter ioc_ops = {
> --- linux-2.6.29-rc5.orig/drivers/i2c/busses/i2c-ixp2000.c 2009-02-22 12:32:33.000000000 +0100
> +++ linux-2.6.29-rc5/drivers/i2c/busses/i2c-ixp2000.c 2009-02-22 12:32:45.000000000 +0100
> @@ -114,7 +114,7 @@ static int ixp2000_i2c_probe(struct plat
> drv_data->algo_data.getsda = ixp2000_bit_getsda;
> drv_data->algo_data.getscl = ixp2000_bit_getscl;
> drv_data->algo_data.udelay = 6;
> - drv_data->algo_data.timeout = 100;
> + drv_data->algo_data.timeout = HZ;
>
> strlcpy(drv_data->adapter.name, plat_dev->dev.driver->name,
> sizeof(drv_data->adapter.name));
>
>
> --
> Jean Delvare
--
Russell King
Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/
maintainer of:
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] i2c: Make sure i2c_algo_bit_data.timeout is HZ-independent
[not found] ` <20090222125005.75b2d661-ig7AzVSIIG7kN2dkZ6Wm7A@public.gmane.org>
2009-02-22 11:52 ` Lennert Buytenhek
2009-02-22 12:03 ` Russell King
@ 2009-02-23 15:00 ` Lennart Sorensen
[not found] ` <20090223150012.GD23244-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys@public.gmane.org>
2 siblings, 1 reply; 5+ messages in thread
From: Lennart Sorensen @ 2009-02-23 15:00 UTC (permalink / raw)
To: Jean Delvare; +Cc: Linux I2C, Russell King, Lennert Buytenhek
On Sun, Feb 22, 2009 at 12:50:05PM +0100, Jean Delvare wrote:
> i2c_algo_bit_data.timeout is supposed to be in jiffies, so drivers
> should use set this value in terms of HZ.
>
> Ultimately I think this field should be discarded in favor of
> i2c_adapter.timeout, but that's left for a future patch.
>
> Signed-off-by: Jean Delvare <khali-PUYAD+kWke1g9hUCZPvPmw@public.gmane.org>
> Cc: Russell King <rmk+kernel-lFZ/pmaqli7XmaaqVzeoHQ@public.gmane.org>
> Cc: Lennert Buytenhek <kernel-OLH4Qvv75CYX/NnBR394Jw@public.gmane.org>
> Cc: Len Sorensen <lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys@public.gmane.org>
> ---
> drivers/i2c/busses/i2c-acorn.c | 2 +-
> drivers/i2c/busses/i2c-ixp2000.c | 2 +-
> drivers/i2c/busses/scx200_i2c.c | 2 +-
> 3 files changed, 3 insertions(+), 3 deletions(-)
>
> --- linux-2.6.29-rc5.orig/drivers/i2c/busses/scx200_i2c.c 2009-02-22 12:32:33.000000000 +0100
> +++ linux-2.6.29-rc5/drivers/i2c/busses/scx200_i2c.c 2009-02-22 12:32:45.000000000 +0100
> @@ -76,7 +76,7 @@ static struct i2c_algo_bit_data scx200_i
> .getsda = scx200_i2c_getsda,
> .getscl = scx200_i2c_getscl,
> .udelay = 10,
> - .timeout = 100,
> + .timeout = HZ,
> };
OK. Well I know the driver has worked for me with both HZ=100 and now
HZ=1000, so making it consistent sounds good to me. I think a lot of
people thought it was in microseconds or miliseconds.
--
Len Sorensen
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] i2c: Make sure i2c_algo_bit_data.timeout is HZ-independent
[not found] ` <20090223150012.GD23244-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys@public.gmane.org>
@ 2009-02-23 15:20 ` Jean Delvare
0 siblings, 0 replies; 5+ messages in thread
From: Jean Delvare @ 2009-02-23 15:20 UTC (permalink / raw)
To: Lennart Sorensen; +Cc: Linux I2C, Russell King, Lennert Buytenhek
On Mon, 23 Feb 2009 10:00:12 -0500, Lennart Sorensen wrote:
> On Sun, Feb 22, 2009 at 12:50:05PM +0100, Jean Delvare wrote:
> > i2c_algo_bit_data.timeout is supposed to be in jiffies, so drivers
> > should use set this value in terms of HZ.
> >
> > Ultimately I think this field should be discarded in favor of
> > i2c_adapter.timeout, but that's left for a future patch.
> >
> > Signed-off-by: Jean Delvare <khali-PUYAD+kWke1g9hUCZPvPmw@public.gmane.org>
> > Cc: Russell King <rmk+kernel-lFZ/pmaqli7XmaaqVzeoHQ@public.gmane.org>
> > Cc: Lennert Buytenhek <kernel-OLH4Qvv75CYX/NnBR394Jw@public.gmane.org>
> > Cc: Len Sorensen <lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys@public.gmane.org>
> > ---
> > drivers/i2c/busses/i2c-acorn.c | 2 +-
> > drivers/i2c/busses/i2c-ixp2000.c | 2 +-
> > drivers/i2c/busses/scx200_i2c.c | 2 +-
> > 3 files changed, 3 insertions(+), 3 deletions(-)
> >
> > --- linux-2.6.29-rc5.orig/drivers/i2c/busses/scx200_i2c.c 2009-02-22 12:32:33.000000000 +0100
> > +++ linux-2.6.29-rc5/drivers/i2c/busses/scx200_i2c.c 2009-02-22 12:32:45.000000000 +0100
> > @@ -76,7 +76,7 @@ static struct i2c_algo_bit_data scx200_i
> > .getsda = scx200_i2c_getsda,
> > .getscl = scx200_i2c_getscl,
> > .udelay = 10,
> > - .timeout = 100,
> > + .timeout = HZ,
> > };
>
> OK. Well I know the driver has worked for me with both HZ=100 and now
> HZ=1000, so making it consistent sounds good to me. I think a lot of
> people thought it was in microseconds or miliseconds.
It was clarified in i2c-algo-bit.h in kernel version 2.5.54, that's
quite a while ago. The problem is that i2c-algo-bit.c itself had it
wrong.
At HZ=1000, 100 jiffies is 100 ms, that's already a reasonably long
timeout. And not that many slaves actually stretch the I2C clock.
--
Jean Delvare
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2009-02-23 15:20 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2009-02-22 11:50 [PATCH] i2c: Make sure i2c_algo_bit_data.timeout is HZ-independent Jean Delvare
[not found] ` <20090222125005.75b2d661-ig7AzVSIIG7kN2dkZ6Wm7A@public.gmane.org>
2009-02-22 11:52 ` Lennert Buytenhek
2009-02-22 12:03 ` Russell King
2009-02-23 15:00 ` Lennart Sorensen
[not found] ` <20090223150012.GD23244-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys@public.gmane.org>
2009-02-23 15:20 ` Jean Delvare
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox