* [PATCH] video/smscufx: fix line counting in fb_write
@ 2012-04-20 22:11 Alexander Holler
2012-04-21 11:26 ` Alexander Holler
0 siblings, 1 reply; 6+ messages in thread
From: Alexander Holler @ 2012-04-20 22:11 UTC (permalink / raw)
To: linux-kernel; +Cc: Steve Glendinning, linux-fbdev, Alexander Holler
Line 0 and 1 were both written to line 0 (on the display) and all subsequent
lines had an offset of -1. The result was that the last line on the display
was never overwritten by writes to /dev/fbN.
The origin of this bug seems to have been udlfb.
Signed-off-by: Alexander Holler <holler@ahsoftware.de>
---
drivers/video/smscufx.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/drivers/video/smscufx.c b/drivers/video/smscufx.c
index ccbfef5..1e1e2d2 100644
--- a/drivers/video/smscufx.c
+++ b/drivers/video/smscufx.c
@@ -904,7 +904,7 @@ static ssize_t ufx_ops_write(struct fb_info *info, const char __user *buf,
result = fb_sys_write(info, buf, count, ppos);
if (result > 0) {
- int start = max((int)(offset / info->fix.line_length) - 1, 0);
+ int start = max((int)(offset / info->fix.line_length), 0);
int lines = min((u32)((result / info->fix.line_length) + 1),
(u32)info->var.yres);
--
1.7.6.5
^ permalink raw reply related [flat|nested] 6+ messages in thread* Re: [PATCH] video/smscufx: fix line counting in fb_write
2012-04-20 22:11 [PATCH] video/smscufx: fix line counting in fb_write Alexander Holler
@ 2012-04-21 11:26 ` Alexander Holler
2012-05-13 12:47 ` Florian Tobias Schandinat
0 siblings, 1 reply; 6+ messages in thread
From: Alexander Holler @ 2012-04-21 11:26 UTC (permalink / raw)
To: Alexander Holler; +Cc: linux-kernel, linux-fbdev
Hello,
as for the patch for udlfb, I forgot to mention that this is a candidate
for all stable trees 3.2 and above.
Btw., the address of the maintainer doesn't seem to be valid anymore.
Regards,
Alexander
Am 21.04.2012 00:11, schrieb Alexander Holler:
> Line 0 and 1 were both written to line 0 (on the display) and all subsequent
> lines had an offset of -1. The result was that the last line on the display
> was never overwritten by writes to /dev/fbN.
>
> The origin of this bug seems to have been udlfb.
>
> Signed-off-by: Alexander Holler<holler@ahsoftware.de>
Cc: stable@vger.kernel.org
> ---
> drivers/video/smscufx.c | 2 +-
> 1 files changed, 1 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/video/smscufx.c b/drivers/video/smscufx.c
> index ccbfef5..1e1e2d2 100644
> --- a/drivers/video/smscufx.c
> +++ b/drivers/video/smscufx.c
> @@ -904,7 +904,7 @@ static ssize_t ufx_ops_write(struct fb_info *info, const char __user *buf,
> result = fb_sys_write(info, buf, count, ppos);
>
> if (result> 0) {
> - int start = max((int)(offset / info->fix.line_length) - 1, 0);
> + int start = max((int)(offset / info->fix.line_length), 0);
> int lines = min((u32)((result / info->fix.line_length) + 1),
> (u32)info->var.yres);
>
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] video/smscufx: fix line counting in fb_write
2012-04-21 11:26 ` Alexander Holler
@ 2012-05-13 12:47 ` Florian Tobias Schandinat
2012-07-02 21:25 ` Alexander Holler
0 siblings, 1 reply; 6+ messages in thread
From: Florian Tobias Schandinat @ 2012-05-13 12:47 UTC (permalink / raw)
To: Alexander Holler; +Cc: linux-kernel, linux-fbdev
Hi Alexander,
On 04/21/2012 11:26 AM, Alexander Holler wrote:
> Hello,
>
> as for the patch for udlfb, I forgot to mention that this is a candidate
> for all stable trees 3.2 and above.
>
> Btw., the address of the maintainer doesn't seem to be valid anymore.
it is better to cc me on patches to the framebuffer subsystem for such
cases. I don't have much free time so it's rare that I come around to
dig in the mailing list.
>
> Regards,
>
> Alexander
>
> Am 21.04.2012 00:11, schrieb Alexander Holler:
>> Line 0 and 1 were both written to line 0 (on the display) and all
>> subsequent
>> lines had an offset of -1. The result was that the last line on the
>> display
>> was never overwritten by writes to /dev/fbN.
>>
>> The origin of this bug seems to have been udlfb.
>>
>> Signed-off-by: Alexander Holler<holler@ahsoftware.de>
>
> Cc: stable@vger.kernel.org
Patch looks good to me but can be made simpler.
>
>> ---
>> drivers/video/smscufx.c | 2 +-
>> 1 files changed, 1 insertions(+), 1 deletions(-)
>>
>> diff --git a/drivers/video/smscufx.c b/drivers/video/smscufx.c
>> index ccbfef5..1e1e2d2 100644
>> --- a/drivers/video/smscufx.c
>> +++ b/drivers/video/smscufx.c
>> @@ -904,7 +904,7 @@ static ssize_t ufx_ops_write(struct fb_info *info,
>> const char __user *buf,
>> result = fb_sys_write(info, buf, count, ppos);
>>
>> if (result> 0) {
>> - int start = max((int)(offset / info->fix.line_length) - 1, 0);
>> + int start = max((int)(offset / info->fix.line_length), 0);
the cast to int as well as the max is superfluous without the -1 as the
value can no longer be negative.
>> int lines = min((u32)((result / info->fix.line_length) + 1),
>> (u32)info->var.yres);
>>
>
Best regards,
Florian Tobias Schandinat
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] video/smscufx: fix line counting in fb_write
2012-05-13 12:47 ` Florian Tobias Schandinat
@ 2012-07-02 21:25 ` Alexander Holler
2012-07-26 17:26 ` Florian Tobias Schandinat
0 siblings, 1 reply; 6+ messages in thread
From: Alexander Holler @ 2012-07-02 21:25 UTC (permalink / raw)
To: Florian Tobias Schandinat; +Cc: linux-kernel, linux-fbdev
Hi Florian,
sorry for the late answer.
Am 13.05.2012 14:47, schrieb Florian Tobias Schandinat:
> Hi Alexander,
>
> On 04/21/2012 11:26 AM, Alexander Holler wrote:
>> Hello,
>>
>> as for the patch for udlfb, I forgot to mention that this is a candidate
>> for all stable trees 3.2 and above.
>>
>> Btw., the address of the maintainer doesn't seem to be valid anymore.
>
> it is better to cc me on patches to the framebuffer subsystem for such
> cases. I don't have much free time so it's rare that I come around to
> dig in the mailing list.
>
>>
>> Regards,
>>
>> Alexander
>>
>> Am 21.04.2012 00:11, schrieb Alexander Holler:
>>> Line 0 and 1 were both written to line 0 (on the display) and all
>>> subsequent
>>> lines had an offset of -1. The result was that the last line on the
>>> display
>>> was never overwritten by writes to /dev/fbN.
>>>
>>> The origin of this bug seems to have been udlfb.
>>>
>>> Signed-off-by: Alexander Holler<holler@ahsoftware.de>
>>
>> Cc: stable@vger.kernel.org
>
> Patch looks good to me but can be made simpler.
>
>>
>>> ---
>>> drivers/video/smscufx.c | 2 +-
>>> 1 files changed, 1 insertions(+), 1 deletions(-)
>>>
>>> diff --git a/drivers/video/smscufx.c b/drivers/video/smscufx.c
>>> index ccbfef5..1e1e2d2 100644
>>> --- a/drivers/video/smscufx.c
>>> +++ b/drivers/video/smscufx.c
>>> @@ -904,7 +904,7 @@ static ssize_t ufx_ops_write(struct fb_info *info,
>>> const char __user *buf,
>>> result = fb_sys_write(info, buf, count, ppos);
>>>
>>> if (result> 0) {
>>> - int start = max((int)(offset / info->fix.line_length) - 1, 0);
>>> + int start = max((int)(offset / info->fix.line_length), 0);
>
> the cast to int as well as the max is superfluous without the -1 as the
> value can no longer be negative.
I had that impression too, but I wanted to change as less as possible,
so I didn't had the need to check types and (their) sizes for possible
overflows or such. I was lazy and just wanted to fix that one bug. ;)
>
>>> int lines = min((u32)((result / info->fix.line_length) + 1),
>>> (u32)info->var.yres);
>>>
Regards,
Alexander
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] video/smscufx: fix line counting in fb_write
2012-07-02 21:25 ` Alexander Holler
@ 2012-07-26 17:26 ` Florian Tobias Schandinat
2012-07-30 19:28 ` Alexander Holler
0 siblings, 1 reply; 6+ messages in thread
From: Florian Tobias Schandinat @ 2012-07-26 17:26 UTC (permalink / raw)
To: Alexander Holler; +Cc: linux-kernel, linux-fbdev
On 07/02/2012 09:25 PM, Alexander Holler wrote:
> Hi Florian,
>
> sorry for the late answer.
>
> Am 13.05.2012 14:47, schrieb Florian Tobias Schandinat:
>> Hi Alexander,
>>
>> On 04/21/2012 11:26 AM, Alexander Holler wrote:
>>> Hello,
>>>
>>> as for the patch for udlfb, I forgot to mention that this is a candidate
>>> for all stable trees 3.2 and above.
>>>
>>> Btw., the address of the maintainer doesn't seem to be valid anymore.
>>
>> it is better to cc me on patches to the framebuffer subsystem for such
>> cases. I don't have much free time so it's rare that I come around to
>> dig in the mailing list.
>>
>>>
>>> Regards,
>>>
>>> Alexander
>>>
>>> Am 21.04.2012 00:11, schrieb Alexander Holler:
>>>> Line 0 and 1 were both written to line 0 (on the display) and all
>>>> subsequent
>>>> lines had an offset of -1. The result was that the last line on the
>>>> display
>>>> was never overwritten by writes to /dev/fbN.
>>>>
>>>> The origin of this bug seems to have been udlfb.
>>>>
>>>> Signed-off-by: Alexander Holler<holler@ahsoftware.de>
>>>
>>> Cc: stable@vger.kernel.org
>>
>> Patch looks good to me but can be made simpler.
>>
>>>
>>>> ---
>>>> drivers/video/smscufx.c | 2 +-
>>>> 1 files changed, 1 insertions(+), 1 deletions(-)
>>>>
>>>> diff --git a/drivers/video/smscufx.c b/drivers/video/smscufx.c
>>>> index ccbfef5..1e1e2d2 100644
>>>> --- a/drivers/video/smscufx.c
>>>> +++ b/drivers/video/smscufx.c
>>>> @@ -904,7 +904,7 @@ static ssize_t ufx_ops_write(struct fb_info *info,
>>>> const char __user *buf,
>>>> result = fb_sys_write(info, buf, count, ppos);
>>>>
>>>> if (result> 0) {
>>>> - int start = max((int)(offset / info->fix.line_length) - 1, 0);
>>>> + int start = max((int)(offset / info->fix.line_length), 0);
>>
>> the cast to int as well as the max is superfluous without the -1 as the
>> value can no longer be negative.
>
> I had that impression too, but I wanted to change as less as possible,
> so I didn't had the need to check types and (their) sizes for possible
> overflows or such. I was lazy and just wanted to fix that one bug. ;)
Well, as this patch fixes a bug I applied it as is.
>
>>
>>>> int lines = min((u32)((result / info->fix.line_length) + 1),
>>>> (u32)info->var.yres);
>>>>
Best regards,
Florian Tobias Schandinat
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2012-07-30 19:28 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
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2012-04-20 22:11 [PATCH] video/smscufx: fix line counting in fb_write Alexander Holler
2012-04-21 11:26 ` Alexander Holler
2012-05-13 12:47 ` Florian Tobias Schandinat
2012-07-02 21:25 ` Alexander Holler
2012-07-26 17:26 ` Florian Tobias Schandinat
2012-07-30 19:28 ` Alexander Holler
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