diff mbox

arch/arm/plat-omap: initializing dma_lch_count, before judging omap_dma_reserve_channels

Message ID 50EE9815.2080402@asianux.com (mailing list archive)
State New, archived
Headers show

Commit Message

Chen Gang Jan. 10, 2013, 10:29 a.m. UTC
dma_lch_count is zero before 1st call of omap_system_dma_probe.
  omap_dma_reserve_channels has value before 1st call of omap_system_dma_probe

  when 1st call of omap_system_dma_probe
    we need set dma_lch_count before use it for judging
    or which will be failed for omap_dma_reserve_channels

  additional info:
    this patch is only for fixing bug, not touch the features.
    so, not use d->lch_count instead of dma_lch_count for the statement:

                        && (omap_dma_reserve_channels <= dma_lch_count))

    at least, now, current fixing is equal to above.
    in the future
      maybe omap_dma_reserve_channels can be set by outside (such as from /proc)
      dma_lch_count is a static global variable which has effect to all devices.
      maybe the original author do not hope the newer is larger than the older

Signed-off-by: Chen Gang <gang.chen@asianux.com>
---
 arch/arm/plat-omap/dma.c |    3 +++
 1 file changed, 3 insertions(+)

Comments

Santosh Shilimkar Jan. 10, 2013, 10:48 a.m. UTC | #1
On Thursday 10 January 2013 03:59 PM, Chen Gang wrote:
>
>    dma_lch_count is zero before 1st call of omap_system_dma_probe.
>    omap_dma_reserve_channels has value before 1st call of omap_system_dma_probe
>
>    when 1st call of omap_system_dma_probe
>      we need set dma_lch_count before use it for judging
>      or which will be failed for omap_dma_reserve_channels
>
>    additional info:
>      this patch is only for fixing bug, not touch the features.
>      so, not use d->lch_count instead of dma_lch_count for the statement:
>
>                          && (omap_dma_reserve_channels <= dma_lch_count))
>
Why not ? Infact thats the right fix as mentioned in the review.

>      at least, now, current fixing is equal to above.
>      in the future
>        maybe omap_dma_reserve_channels can be set by outside (such as from /proc)
>        dma_lch_count is a static global variable which has effect to all devices.
>        maybe the original author do not hope the newer is larger than the older
>
'omap_dma_reserve_channels' when used is suppose to be from command
line. Hence the proposed fix in the review is the right one.

Regards
santosh

--
To unsubscribe from this list: send the line "unsubscribe linux-omap" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Santosh Shilimkar Jan. 10, 2013, 10:51 a.m. UTC | #2
On Thursday 10 January 2013 04:18 PM, Santosh Shilimkar wrote:
> On Thursday 10 January 2013 03:59 PM, Chen Gang wrote:
>>
>>    dma_lch_count is zero before 1st call of omap_system_dma_probe.
>>    omap_dma_reserve_channels has value before 1st call of
>> omap_system_dma_probe
>>
>>    when 1st call of omap_system_dma_probe
>>      we need set dma_lch_count before use it for judging
>>      or which will be failed for omap_dma_reserve_channels
>>
>>    additional info:
>>      this patch is only for fixing bug, not touch the features.
>>      so, not use d->lch_count instead of dma_lch_count for the statement:
>>
>>                          && (omap_dma_reserve_channels <= dma_lch_count))
>>
> Why not ? Infact thats the right fix as mentioned in the review.
>
>>      at least, now, current fixing is equal to above.
>>      in the future
>>        maybe omap_dma_reserve_channels can be set by outside (such as
>> from /proc)
>>        dma_lch_count is a static global variable which has effect to
>> all devices.
>>        maybe the original author do not hope the newer is larger than
>> the older
>>
> 'omap_dma_reserve_channels' when used is suppose to be from command
> line. Hence the proposed fix in the review is the right one.
>
Another thing. please fix the subject line. It should be something like
below.

ARM: OMAP: Fix the use of uninitialized dma_lch_count

Regards
santosh
--
To unsubscribe from this list: send the line "unsubscribe linux-omap" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Chen Gang Jan. 11, 2013, 5:03 a.m. UTC | #3
? 2013?01?10? 18:48, Santosh Shilimkar ??:
> 'omap_dma_reserve_channels' when used is suppose to be from command
> line. Hence the proposed fix in the review is the right one.

  ok, thank you for your suggestion.

  I will send patch v2, also mark you as Signed-of-by.

  :-)
Chen Gang Jan. 11, 2013, 5:09 a.m. UTC | #4
? 2013?01?10? 18:51, Santosh Shilimkar ??:
> Another thing. please fix the subject line. It should be something like
> below.
> 
> ARM: OMAP: Fix the use of uninitialized dma_lch_count

  ok, thank you for your suggestion

  I will use it as subject for patch v2.

  :-)
Santosh Shilimkar Jan. 11, 2013, 7:26 a.m. UTC | #5
On Friday 11 January 2013 10:33 AM, Chen Gang wrote:
> ? 2013?01?10? 18:48, Santosh Shilimkar ??:
>> 'omap_dma_reserve_channels' when used is suppose to be from command
>> line. Hence the proposed fix in the review is the right one.
> 
>    ok, thank you for your suggestion.
> 
>    I will send patch v2, also mark you as Signed-of-by.
> 
Acked-by: is just fine.

--
To unsubscribe from this list: send the line "unsubscribe linux-omap" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Chen Gang Jan. 11, 2013, 11:24 a.m. UTC | #6
? 2013?01?11? 15:26, Santosh Shilimkar ??:
> On Friday 11 January 2013 10:33 AM, Chen Gang wrote:
>> ?? 2013??01??10?? 18:48, Santosh Shilimkar ???:
>>> 'omap_dma_reserve_channels' when used is suppose to be from command
>>> line. Hence the proposed fix in the review is the right one.
>>
>>    ok, thank you for your suggestion.
>>
>>    I will send patch v2, also mark you as Signed-of-by.
>>
> Acked-by: is just fine.
> 
> 
> 
  thanks, I have send patch v2 for it, since it is a new subject, so
still use [PATCH] instead of [PATCH v2].

  the subject of the new patch (which has sent) is:
    [PATCH] ARM: OMAP: Fix the use of uninitialized dma_lch_count

  please check, thanks.
diff mbox

Patch

diff --git a/arch/arm/plat-omap/dma.c b/arch/arm/plat-omap/dma.c
index 4136b20..b382eef 100644
--- a/arch/arm/plat-omap/dma.c
+++ b/arch/arm/plat-omap/dma.c
@@ -2018,6 +2018,9 @@  static int omap_system_dma_probe(struct platform_device *pdev)
 	d			= p->dma_attr;
 	errata			= p->errata;
 
+	if (!dma_lch_count)
+		dma_lch_count	= d->lch_count;
+
 	if ((d->dev_caps & RESERVE_CHANNEL) && omap_dma_reserve_channels
 			&& (omap_dma_reserve_channels <= dma_lch_count))
 		d->lch_count	= omap_dma_reserve_channels;