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| author | Takashi Sakamoto <o-takashi@sakamocchi.jp> | 2024-09-04 21:51:50 +0900 |
|---|---|---|
| committer | Takashi Sakamoto <o-takashi@sakamocchi.jp> | 2024-09-04 21:51:50 +0900 |
| commit | c6fb88a5270f4ba24859f5ecb61cfc731ef16300 (patch) | |
| tree | 19f47ec8e4fc3fc44e7e8c7c853fa8b55bcc4894 /drivers/firewire/core.h | |
| parent | 7d35a0060392af796cc4e08780d7b71d1fc71e5e (diff) | |
firewire: core: allocate workqueue to handle isochronous contexts in card
This commit adds a workqueue dedicated for isochronous context processing.
The workqueue is allocated per instance of fw_card structure to satisfy the
following characteristics descending from 1394 OHCI specification:
In 1394 OHCI specification, memory pages are reserved to each isochronous
context dedicated to DMA transmission. It allows to operate these
per-context pages concurrently. Software can schedule hardware interrupt
for several isochronous context to the same cycle, thus WQ_UNBOUND is
specified. Additionally, it is sleepable to operate the content of pages,
thus WQ_BH is not used.
The isochronous context delivers the packets with time stamp, thus
WQ_HIGHPRI is specified for semi real-time data such as IEC 61883-1/6
protocol implemented by ALSA firewire stack. The isochronous context is not
used by the implementation of SCSI over IEEE1394 protocol (sbp2), thus
WQ_MEM_RECLAIM is not specified.
It is useful for users to adjust cpu affinity of the workqueue depending
on their work loads, thus WQ_SYS is specified to expose the attributes to
user space.
Tested-by: Edmund Raile <edmund.raile@protonmail.com>
Link: https://lore.kernel.org/r/20240904125155.461886-2-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Diffstat (limited to 'drivers/firewire/core.h')
| -rw-r--r-- | drivers/firewire/core.h | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/firewire/core.h b/drivers/firewire/core.h index 57d101c01e36..96ae366889e0 100644 --- a/drivers/firewire/core.h +++ b/drivers/firewire/core.h @@ -115,8 +115,8 @@ struct fw_card_driver { void fw_card_initialize(struct fw_card *card, const struct fw_card_driver *driver, struct device *device); -int fw_card_add(struct fw_card *card, - u32 max_receive, u32 link_speed, u64 guid); +int fw_card_add(struct fw_card *card, u32 max_receive, u32 link_speed, u64 guid, + unsigned int supported_isoc_contexts); void fw_core_remove_card(struct fw_card *card); int fw_compute_block_crc(__be32 *block); void fw_schedule_bm_work(struct fw_card *card, unsigned long delay); |