On Tue, Dec 17, 2019 at 11:41 AM Peter Ujfalusi <[email protected]> wrote:
> dma_request_slave_channel() is a wrapper on top of dma_request_chan()
> eating up the error code.
>
> By using dma_request_chan() directly the driver can support deferred
> probing against DMA.
>
> Signed-off-by: Peter Ujfalusi <[email protected]>
Reviewed-by: Geert Uytterhoeven <[email protected]>
One comment below.
> --- a/drivers/media/platform/rcar_drif.c
> +++ b/drivers/media/platform/rcar_drif.c
> @@ -275,10 +275,10 @@ static int rcar_drif_alloc_dmachannels(struct rcar_drif_sdr *sdr)
> for_each_rcar_drif_channel(i, &sdr->cur_ch_mask) {
> struct rcar_drif *ch = sdr->ch[i];
>
> - ch->dmach = dma_request_slave_channel(&ch->pdev->dev, "rx");
> - if (!ch->dmach) {
> + ch->dmach = dma_request_chan(&ch->pdev->dev, "rx");
> + if (IS_ERR(ch->dmach)) {
> rdrif_err(sdr, "ch%u: dma channel req failed\n", i);
Now there is an error code, you might (1) want to print it, and (2) only
do so when it is not due to probe deferral:
if (PTR_ERR(ch->dmach) != -EPROBE_DEFER)
rdrif_err(sdr, "ch%u: dma channel req failed %pe\n",
i, ch->dmach);
> - ret = -ENODEV;
> + ret = PTR_ERR(ch->dmach);
> goto dmach_error;
> }
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- [email protected]
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
Hi Geert,
On 20/01/2020 14.05, Geert Uytterhoeven wrote:
> On Tue, Dec 17, 2019 at 11:41 AM Peter Ujfalusi <[email protected]> wrote:
>> dma_request_slave_channel() is a wrapper on top of dma_request_chan()
>> eating up the error code.
>>
>> By using dma_request_chan() directly the driver can support deferred
>> probing against DMA.
>>
>> Signed-off-by: Peter Ujfalusi <[email protected]>
>
> Reviewed-by: Geert Uytterhoeven <[email protected]>
>
> One comment below.
>
>> --- a/drivers/media/platform/rcar_drif.c
>> +++ b/drivers/media/platform/rcar_drif.c
>> @@ -275,10 +275,10 @@ static int rcar_drif_alloc_dmachannels(struct rcar_drif_sdr *sdr)
>> for_each_rcar_drif_channel(i, &sdr->cur_ch_mask) {
>> struct rcar_drif *ch = sdr->ch[i];
>>
>> - ch->dmach = dma_request_slave_channel(&ch->pdev->dev, "rx");
>> - if (!ch->dmach) {
>> + ch->dmach = dma_request_chan(&ch->pdev->dev, "rx");
>> + if (IS_ERR(ch->dmach)) {
>> rdrif_err(sdr, "ch%u: dma channel req failed\n", i);
>
> Now there is an error code, you might (1) want to print it, and (2) only
> do so when it is not due to probe deferral:
>
> if (PTR_ERR(ch->dmach) != -EPROBE_DEFER)
> rdrif_err(sdr, "ch%u: dma channel req failed %pe\n",
> i, ch->dmach);
Yes, this is true.
>
>> - ret = -ENODEV;
>> + ret = PTR_ERR(ch->dmach);
if (ret != -EPROBE_DEFER)
rdrif_err(sdr, "ch%u: dma channel req failed (%d)\n", i, ret);
might be simpler.
>> goto dmach_error;
>> }
>
> Gr{oetje,eeting}s,
>
> Geert
>
- Péter
Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki.
Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki
Hi Peter,
On Mon, Jan 20, 2020 at 1:09 PM Peter Ujfalusi <[email protected]> wrote:
> On 20/01/2020 14.05, Geert Uytterhoeven wrote:
> > On Tue, Dec 17, 2019 at 11:41 AM Peter Ujfalusi <[email protected]> wrote:
> >> dma_request_slave_channel() is a wrapper on top of dma_request_chan()
> >> eating up the error code.
> >>
> >> By using dma_request_chan() directly the driver can support deferred
> >> probing against DMA.
> >>
> >> Signed-off-by: Peter Ujfalusi <[email protected]>
> >
> > Reviewed-by: Geert Uytterhoeven <[email protected]>
> >
> > One comment below.
> >
> >> --- a/drivers/media/platform/rcar_drif.c
> >> +++ b/drivers/media/platform/rcar_drif.c
> >> @@ -275,10 +275,10 @@ static int rcar_drif_alloc_dmachannels(struct rcar_drif_sdr *sdr)
> >> for_each_rcar_drif_channel(i, &sdr->cur_ch_mask) {
> >> struct rcar_drif *ch = sdr->ch[i];
> >>
> >> - ch->dmach = dma_request_slave_channel(&ch->pdev->dev, "rx");
> >> - if (!ch->dmach) {
> >> + ch->dmach = dma_request_chan(&ch->pdev->dev, "rx");
> >> + if (IS_ERR(ch->dmach)) {
> >> rdrif_err(sdr, "ch%u: dma channel req failed\n", i);
> >
> > Now there is an error code, you might (1) want to print it, and (2) only
> > do so when it is not due to probe deferral:
> >
> > if (PTR_ERR(ch->dmach) != -EPROBE_DEFER)
> > rdrif_err(sdr, "ch%u: dma channel req failed %pe\n",
> > i, ch->dmach);
>
> Yes, this is true.
>
> >
> >> - ret = -ENODEV;
> >> + ret = PTR_ERR(ch->dmach);
>
> if (ret != -EPROBE_DEFER)
> rdrif_err(sdr, "ch%u: dma channel req failed (%d)\n", i, ret);
>
> might be simpler.
Sure, checking ret is simpler.
But printing ch->dmach means you can use the new %pe format specifier
to pretty-print the error code.
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- [email protected]
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
On 20/01/2020 14.36, Geert Uytterhoeven wrote:
> Hi Peter,
>
> On Mon, Jan 20, 2020 at 1:09 PM Peter Ujfalusi <[email protected]> wrote:
>> On 20/01/2020 14.05, Geert Uytterhoeven wrote:
>>> On Tue, Dec 17, 2019 at 11:41 AM Peter Ujfalusi <[email protected]> wrote:
>>>> dma_request_slave_channel() is a wrapper on top of dma_request_chan()
>>>> eating up the error code.
>>>>
>>>> By using dma_request_chan() directly the driver can support deferred
>>>> probing against DMA.
>>>>
>>>> Signed-off-by: Peter Ujfalusi <[email protected]>
>>>
>>> Reviewed-by: Geert Uytterhoeven <[email protected]>
>>>
>>> One comment below.
>>>
>>>> --- a/drivers/media/platform/rcar_drif.c
>>>> +++ b/drivers/media/platform/rcar_drif.c
>>>> @@ -275,10 +275,10 @@ static int rcar_drif_alloc_dmachannels(struct rcar_drif_sdr *sdr)
>>>> for_each_rcar_drif_channel(i, &sdr->cur_ch_mask) {
>>>> struct rcar_drif *ch = sdr->ch[i];
>>>>
>>>> - ch->dmach = dma_request_slave_channel(&ch->pdev->dev, "rx");
>>>> - if (!ch->dmach) {
>>>> + ch->dmach = dma_request_chan(&ch->pdev->dev, "rx");
>>>> + if (IS_ERR(ch->dmach)) {
>>>> rdrif_err(sdr, "ch%u: dma channel req failed\n", i);
>>>
>>> Now there is an error code, you might (1) want to print it, and (2) only
>>> do so when it is not due to probe deferral:
>>>
>>> if (PTR_ERR(ch->dmach) != -EPROBE_DEFER)
>>> rdrif_err(sdr, "ch%u: dma channel req failed %pe\n",
>>> i, ch->dmach);
>>
>> Yes, this is true.
>>
>>>
>>>> - ret = -ENODEV;
>>>> + ret = PTR_ERR(ch->dmach);
>>
>> if (ret != -EPROBE_DEFER)
>> rdrif_err(sdr, "ch%u: dma channel req failed (%d)\n", i, ret);
>>
>> might be simpler.
>
> Sure, checking ret is simpler.
> But printing ch->dmach means you can use the new %pe format specifier
> to pretty-print the error code.
Ah, I was not aware of this, but there is another issue with the patch:
I need to set the ch->dmach to NULL before jumping to dmach_error..
I'll send v3 in a minute.
>
> Gr{oetje,eeting}s,
>
> Geert
>
- Péter
Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki.
Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki