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| author | Takashi Sakamoto <o-takashi@sakamocchi.jp> | 2024-09-09 23:00:18 +0900 |
|---|---|---|
| committer | Takashi Sakamoto <o-takashi@sakamocchi.jp> | 2024-09-09 23:00:18 +0900 |
| commit | f877f1d81b2ffcac341ff62ae076d7ad5ba83f46 (patch) | |
| tree | 59972947210c65a5932c97a2dc76fe44f1b4e451 | |
| parent | e97fb38fa1404abef72bac7de2c5bf2bbab4d93b (diff) | |
| download | linux-f877f1d81b2ffcac341ff62ae076d7ad5ba83f46.tar.gz linux-f877f1d81b2ffcac341ff62ae076d7ad5ba83f46.tar.bz2 linux-f877f1d81b2ffcac341ff62ae076d7ad5ba83f46.zip | |
firewire: core: use mutex to coordinate concurrent calls to flush completions
In current implementation, test_and_set_bit_lock() is used to mediate
concurrent calls of ohci_flush_iso_completions(). However, the ad-hoc
usage of atomic operations is not preferable.
This commit uses mutex_trylock() as the similar operations. The core
function is responsible for the mediation, instead of 1394 OHCI driver.
Link: https://lore.kernel.org/r/20240909140018.65289-3-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
| -rw-r--r-- | drivers/firewire/core-iso.c | 11 | ||||
| -rw-r--r-- | drivers/firewire/ohci.c | 37 | ||||
| -rw-r--r-- | include/linux/firewire.h | 1 |
3 files changed, 24 insertions, 25 deletions
diff --git a/drivers/firewire/core-iso.c b/drivers/firewire/core-iso.c index 9f41c78878ad..1405d2e9cb2c 100644 --- a/drivers/firewire/core-iso.c +++ b/drivers/firewire/core-iso.c @@ -157,6 +157,7 @@ struct fw_iso_context *fw_iso_context_create(struct fw_card *card, ctx->callback.sc = callback; ctx->callback_data = callback_data; INIT_WORK(&ctx->work, flush_completions_work); + mutex_init(&ctx->flushing_completions_mutex); trace_isoc_outbound_allocate(ctx, channel, speed); trace_isoc_inbound_single_allocate(ctx, channel, header_size); @@ -173,6 +174,8 @@ void fw_iso_context_destroy(struct fw_iso_context *ctx) trace_isoc_inbound_multiple_destroy(ctx); ctx->card->driver->free_iso_context(ctx); + + mutex_destroy(&ctx->flushing_completions_mutex); } EXPORT_SYMBOL(fw_iso_context_destroy); @@ -226,7 +229,7 @@ EXPORT_SYMBOL(fw_iso_context_queue_flush); * to process the context asynchronously, fw_iso_context_schedule_flush_completions() is available * instead. * - * Context: Process context. + * Context: Process context due to mutex_trylock(). */ int fw_iso_context_flush_completions(struct fw_iso_context *ctx) { @@ -234,7 +237,11 @@ int fw_iso_context_flush_completions(struct fw_iso_context *ctx) trace_isoc_inbound_single_flush_completions(ctx); trace_isoc_inbound_multiple_flush_completions(ctx); - return ctx->card->driver->flush_iso_completions(ctx); + scoped_cond_guard(mutex_try, /* nothing to do */, &ctx->flushing_completions_mutex) { + return ctx->card->driver->flush_iso_completions(ctx); + } + + return 0; } EXPORT_SYMBOL(fw_iso_context_flush_completions); diff --git a/drivers/firewire/ohci.c b/drivers/firewire/ohci.c index 02ff0363d3ad..b182998a77f4 100644 --- a/drivers/firewire/ohci.c +++ b/drivers/firewire/ohci.c @@ -166,7 +166,6 @@ struct iso_context { struct context context; void *header; size_t header_length; - unsigned long flushing_completions; u32 mc_buffer_bus; u16 mc_completed; u16 last_timestamp; @@ -3579,31 +3578,23 @@ static void ohci_flush_queue_iso(struct fw_iso_context *base) static int ohci_flush_iso_completions(struct fw_iso_context *base) { struct iso_context *ctx = container_of(base, struct iso_context, base); - int ret = 0; - if (!test_and_set_bit_lock(0, &ctx->flushing_completions)) { - // Note that tasklet softIRQ is not used to process isochronous context anymore. - context_tasklet((unsigned long)&ctx->context); + // Note that tasklet softIRQ is not used to process isochronous context anymore. + context_tasklet((unsigned long)&ctx->context); - switch (base->type) { - case FW_ISO_CONTEXT_TRANSMIT: - case FW_ISO_CONTEXT_RECEIVE: - if (ctx->header_length != 0) - flush_iso_completions(ctx, FW_ISO_CONTEXT_COMPLETIONS_CAUSE_FLUSH); - break; - case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL: - if (ctx->mc_completed != 0) - flush_ir_buffer_fill(ctx); - break; - default: - ret = -ENOSYS; - } - - clear_bit_unlock(0, &ctx->flushing_completions); - smp_mb__after_atomic(); + switch (base->type) { + case FW_ISO_CONTEXT_TRANSMIT: + case FW_ISO_CONTEXT_RECEIVE: + if (ctx->header_length != 0) + flush_iso_completions(ctx, FW_ISO_CONTEXT_COMPLETIONS_CAUSE_FLUSH); + return 0; + case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL: + if (ctx->mc_completed != 0) + flush_ir_buffer_fill(ctx); + return 0; + default: + return -ENOSYS; } - - return ret; } static const struct fw_card_driver ohci_driver = { diff --git a/include/linux/firewire.h b/include/linux/firewire.h index f815d12deda0..19e8c5f9537c 100644 --- a/include/linux/firewire.h +++ b/include/linux/firewire.h @@ -512,6 +512,7 @@ union fw_iso_callback { struct fw_iso_context { struct fw_card *card; struct work_struct work; + struct mutex flushing_completions_mutex; int type; int channel; int speed; |