Re: [PATCH 3/4] ACPI: Introduce DMA ranges parsing

From: Rafael J. Wysocki
Date: Mon Jul 24 2017 - 14:42:27 EST


On Mon, Jul 24, 2017 at 12:40 PM, Lorenzo Pieralisi
<lorenzo.pieralisi@xxxxxxx> wrote:
> On Sat, Jul 22, 2017 at 12:15:42AM +0200, Rafael J. Wysocki wrote:
>

[cut]

>
>> > + return -EINVAL;
>> > + }
>> > +
>> > + ret = acpi_dev_get_dma_resources(adev, &list);
>> > + if (ret > 0) {
>> > + list_for_each_entry(rentry, &list, node) {
>> > + if (dma_offset && rentry->offset != dma_offset) {
>> > + ret = -EINVAL;
>> > + pr_warn("Can't handle multiple windows with different offsets\n");
>> > + goto out;
>> > + }
>> > + dma_offset = rentry->offset;
>> > +
>> > + /* Take lower and upper limits */
>> > + if (rentry->res->start < dma_start)
>> > + dma_start = rentry->res->start;
>> > + if (rentry->res->end > dma_end)
>> > + dma_end = rentry->res->end;
>> > + }
>> > +
>> > + if (dma_start >= dma_end) {
>> > + ret = -EINVAL;
>> > + pr_warn("Invalid DMA regions configuration\n");
>>
>> dev_warn()?
>>
>> And why _warn() and not _info()?
>
> Mmm..ok for the dev_ prefix - basically this would be a FW_BUG (I think
> this specific error condition is overkill TBH, the ACPI resource
> validation code should catch it before we even get here) not sure
> about downgrading it to _info() though, I would leave it at this
> loglevel - in particular in the offset check above:
>
> if (dma_offset && rentry->offset != dma_offset) {
> ret = -EINVAL;
> pr_warn("Can't handle multiple windows with different offsets\n");
> goto out;
> }

Well, so the "why" question above still has no answer ...