Messages in this thread | | | Subject | Re: [PATCH v5 2/5] firmware: encapsulate firmware loading status | From | Daniel Wagner <> | Date | Fri, 7 Oct 2016 13:41:21 +0200 |
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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
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