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Groups > linux.kernel > #1568429 > unrolled thread
| Started by | Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com> |
|---|---|
| First post | 2017-01-27 16:20 +0100 |
| Last post | 2017-01-30 02:20 +0100 |
| Articles | 5 — 3 participants |
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[PATCH] i2c: piix4: Fix request_region size Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com> - 2017-01-27 16:20 +0100
Re: [PATCH] i2c: piix4: Fix request_region size Jean Delvare <jdelvare@suse.de> - 2017-01-28 09:40 +0100
Re: [PATCH] i2c: piix4: Fix request_region size Wolfram Sang <wsa@the-dreams.de> - 2017-01-28 12:10 +0100
Re: [PATCH] i2c: piix4: Fix request_region size Jean Delvare <jdelvare@suse.de> - 2017-01-28 12:20 +0100
Re: [PATCH] i2c: piix4: Fix request_region size Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com> - 2017-01-30 02:20 +0100
| From | Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com> |
|---|---|
| Date | 2017-01-27 16:20 +0100 |
| Subject | [PATCH] i2c: piix4: Fix request_region size |
| Message-ID | <t4gtI-5Mm-23@gated-at.bofh.it> |
Since '701dc207bf55 ("i2c: piix4: Avoid race conditions with IMC")' we
are using the SMBSLVCNT register at offset 0x8. We need to request it.
Fixes: 701dc207bf55 ("i2c: piix4: Avoid race conditions with IMC")
Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
---
Please note, not tested on hardware.
drivers/i2c/busses/i2c-piix4.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/i2c/busses/i2c-piix4.c b/drivers/i2c/busses/i2c-piix4.c
index e34d82e79b98..73cc6799cc59 100644
--- a/drivers/i2c/busses/i2c-piix4.c
+++ b/drivers/i2c/busses/i2c-piix4.c
@@ -58,7 +58,7 @@
#define SMBSLVDAT (0xC + piix4_smba)
/* count for request_region */
-#define SMBIOSIZE 8
+#define SMBIOSIZE 9
/* PCI Address Constants */
#define SMBBA 0x090
--
2.11.0
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| From | Jean Delvare <jdelvare@suse.de> |
|---|---|
| Date | 2017-01-28 09:40 +0100 |
| Message-ID | <t4wI9-7pN-5@gated-at.bofh.it> |
| In reply to | #1568429 |
Hi Ricardo,
On ven., 2017-01-27 at 15:59 +0100, Ricardo Ribalda Delgado wrote:
> Since '701dc207bf55 ("i2c: piix4: Avoid race conditions with IMC")'
> we
> are using the SMBSLVCNT register at offset 0x8. We need to request
> it.
>
> Fixes: 701dc207bf55 ("i2c: piix4: Avoid race conditions with IMC")
> Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
> ---
> Please note, not tested on hardware.
> drivers/i2c/busses/i2c-piix4.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/i2c/busses/i2c-piix4.c b/drivers/i2c/busses/i2c-
> piix4.c
> index e34d82e79b98..73cc6799cc59 100644
> --- a/drivers/i2c/busses/i2c-piix4.c
> +++ b/drivers/i2c/busses/i2c-piix4.c
> @@ -58,7 +58,7 @@
> #define SMBSLVDAT (0xC + piix4_smba)
>
> /* count for request_region */
> -#define SMBIOSIZE 8
> +#define SMBIOSIZE 9
>
Are you certain that all supported devices have this extra register?
>
> /* PCI Address Constants */
> #define SMBBA 0x090
--
Jean Delvare
SUSE L3 Support
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| From | Wolfram Sang <wsa@the-dreams.de> |
|---|---|
| Date | 2017-01-28 12:10 +0100 |
| Message-ID | <t4z3j-CN-5@gated-at.bofh.it> |
| In reply to | #1568848 |
[Multipart message — attachments visible in raw view] — view raw
> > /* count for request_region */ > > -#define SMBIOSIZE 8 > > +#define SMBIOSIZE 9 > > > > Are you certain that all supported devices have this extra register? Isn't it better to have a potentially unused register mapped than a potentially used register unmapped?
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| From | Jean Delvare <jdelvare@suse.de> |
|---|---|
| Date | 2017-01-28 12:20 +0100 |
| Message-ID | <t4zcZ-Gf-5@gated-at.bofh.it> |
| In reply to | #1568867 |
Hi Wolfram, On Sat, 28 Jan 2017 12:00:21 +0100, Wolfram Sang wrote: > > > > /* count for request_region */ > > > -#define SMBIOSIZE 8 > > > +#define SMBIOSIZE 9 > > > > Are you certain that all supported devices have this extra register? > > Isn't it better to have a potentially unused register mapped than a > potentially used register unmapped? My concern is that the region request could fail due to a conflict with another device, if the physical I/O region is only 8 and we try to request 9. -- Jean Delvare SUSE L3 Support
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| From | Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com> |
|---|---|
| Date | 2017-01-30 02:20 +0100 |
| Message-ID | <t58Ns-64o-11@gated-at.bofh.it> |
| In reply to | #1568868 |
Hi Jean and Wolfram On Sat, Jan 28, 2017 at 12:13 PM, Jean Delvare <jdelvare@suse.de> wrote: > Hi Wolfram, > > On Sat, 28 Jan 2017 12:00:21 +0100, Wolfram Sang wrote: >> >> > > /* count for request_region */ >> > > -#define SMBIOSIZE 8 >> > > +#define SMBIOSIZE 9 >> > >> > Are you certain that all supported devices have this extra register? >> >> Isn't it better to have a potentially unused register mapped than a >> potentially used register unmapped We have been "lucky" that it is a ioport and not a mmap region, otherwise we would have seen a nice oops :). > > My concern is that the region request could fail due to a conflict with > another device, if the physical I/O region is only 8 and we try to > request 9. I do not think that this is the case, if you check the top of the file you can see how there are many other definitions for registers. I expect that SMBIOSIZE=8 is just the original author being conservative. Of course I cannot say that there is one platform where one extra ioport can cause a conflict, but I believe that we must request all the ports that we will use. Regards! > > -- > Jean Delvare > SUSE L3 Support -- Ricardo Ribalda
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