On Mon, Jul 24, 2017 at 08:42:15PM +0200, Rafael J. Wysocki wrote:

On Mon, Jul 24, 2017 at 12:40 PM, Lorenzo Pieralisi
[off-list ref] wrote:

quoted

On Sat, Jul 22, 2017 at 12:15:42AM +0200, Rafael J. Wysocki wrote:

[cut]

quoted

quoted

quoted

+           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 ...

It is a firmware misconfiguration, we end up dismissing firmware
information and use the device with default/possibly misconfigured
DMA windows (ie offset == 0) for that platform, that's the reason
why I thought it would deserve a _warn rather than _info loglevel.

Thanks,
Lorenzo