Hi Luis,
On 10/05/2016 10:27 PM, Luis R. Rodriguez wrote:
On Tue, Sep 13, 2016 at 11:47:08AM +0200, Daniel Wagner wrote:
On 09/09/2016 02:12 PM, Daniel Wagner wrote:
The firmware user helper code tracks the current state of the loading
process via unsigned long status and a complection in struct
firmware_buf. We only need this for the usermode helper as such we can
encapsulate all this data into its own data structure.
I don't think we are able to move the completion code into a
CONFIG_FW_LOADER_HELPER section. The direct loading path uses
completion as well.
Where?
If you look at the current code (not these patches) you have dependency
via the firmware_buf for two concurrent _request_firmware() calls:
1nd request (waker context)
_request_firmware()
_request_firmware_prepare()
fw_lookup_and_allocate_buf() # no pendending request
# returns 0 -> load firmware
fw_get_fileystem_firmware()
fw_finish_direct_load()
complete_all()
2nd request (waiter context)
_request_firmware()
_request_firmware_prepare()
fw_lookup_allocate_buf() # finds previously allocated buf
# returns 1 -> wait for loading
sync_cached_firmware_buf()
wait_for_completion_interruptible_timeout()
+#else /* CONFIG_FW_LOADER_USER_HELPER */
+
+#define fw_umh_wait_timeout(fw_st, long) 0
+
+#define fw_umh_done(fw_st)
+#define fw_umh_is_done(fw_st) true
+#define fw_umh_is_aborted(fw_st) false
We still need the implementation for fw_umh_wait_timeout() and
fw_umh_start(), fw_umh_done() etc.
Why?
See above.
@@ -309,8 +373,7 @@ static void fw_finish_direct_load(struct device *device,
struct firmware_buf *buf)
{
mutex_lock(&fw_lock);
- set_bit(FW_STATUS_DONE, &buf->status);
- complete_all(&buf->completion);
+ fw_umh_done(&buf->fw_umh);
mutex_unlock(&fw_lock);
}
Here we signal that we have loaded the firmware
The struct firmware_buf is only used for the sysfs stuff no?
I don't know, I was looking at the code in firmware_class.c not any
users. Why is that important?
/* wait until the shared firmware_buf becomes ready (or error) */
static int sync_cached_firmware_buf(struct firmware_buf *buf)
{
int ret = 0;
mutex_lock(&fw_lock);
- while (!test_bit(FW_STATUS_DONE, &buf->status)) {
- if (is_fw_load_aborted(buf)) {
+ while (!fw_umh_is_done(&buf->fw_umh)) {
+ if (fw_umh_is_aborted(&buf->fw_umh)) {
ret = -ENOENT;
break;
}
mutex_unlock(&fw_lock);
- ret = wait_for_completion_interruptible(&buf->completion);
+ ret = fw_umh_wait_timeout(&buf->fw_umh, 0);
mutex_lock(&fw_lock);
}
and here we here we wait for it.
Likewise.
As I tried to explain above the buffering code is depending on completion.
cheers,
daniel
