On Wed, Aug 19, 2020 at 03:46:30PM +0200, Cezary Rojewski wrote:
On 2020-08-18 1:50 PM, Andy Shevchenko wrote:
On Mon, Aug 17, 2020 at 01:12:01PM +0200, Cezary Rojewski wrote:
On 2020-08-13 8:51 PM, Andy Shevchenko wrote:
On Wed, Aug 12, 2020 at 10:57:42PM +0200, Cezary Rojewski wrote:
...
- bool lp;
- if (list_empty(&cdev->stream_list))
return catpt_dsp_select_lpclock(cdev, true, true);- lp = true;
- list_for_each_entry(stream, &cdev->stream_list, node) {
if (stream->prepared) {lp = false;break;}- }
- return catpt_dsp_select_lpclock(cdev, lp, true);
Seems too much duplication.
struct catpt_stream_runtime *stream;
list_for_each_entry(stream, &cdev->stream_list, node) { if (stream->prepared) return catpt_dsp_select_lpclock(cdev, false, true); }
return catpt_dsp_select_lpclock(cdev, true, true);
Better?
list_first_entry (part of list_for_each_entry) expects list to be non-empty. ->streal_list may be empty when invoking catpt_dsp_update_lpclock().
I didn't get this. Can you point out where is exactly problematic place?
list_for_each_entry makes use of list_first_entry when initializing 'pos' index variable.
Correct.
Documentation for list_first_entry reads: "Note, that list is expected to be not empty"
Correct.
so I'm validating list's status before moving on to the loop as stream_list may be empty when catpt_dsp_update_lpclock() gets called.
But here you missed the second part of the for-loop, i.e. exit conditional.
If your assumption (that list_for_each_*() is not empty-safe) is correct, it would be disaster in global kernel source level.