ALSA: firewire: extend snd_fw_transaction()
Add a flag to snd_fw_transaction() to allow it to abort when a bus reset
happens. This removes most of the duplicated error handling loops that
were required around calls to the low-level fw_run_transaction().
Also add a flag to suppress error messages; errors are expected when we
attempt to clean up after the device was unplugged.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
diff --git a/sound/firewire/lib.c b/sound/firewire/lib.c
index 14eb414..7409edb 100644
--- a/sound/firewire/lib.c
+++ b/sound/firewire/lib.c
@@ -11,7 +11,7 @@
#include <linux/module.h>
#include "lib.h"
-#define ERROR_RETRY_DELAY_MS 5
+#define ERROR_RETRY_DELAY_MS 20
/**
* snd_fw_transaction - send a request and wait for its completion
@@ -20,6 +20,9 @@
* @offset: the address in the target's address space
* @buffer: input/output data
* @length: length of @buffer
+ * @flags: use %FW_FIXED_GENERATION and add the generation value to attempt the
+ * request only in that generation; use %FW_QUIET to suppress error
+ * messages
*
* Submits an asynchronous request to the target device, and waits for the
* response. The node ID and the current generation are derived from @unit.
@@ -27,14 +30,18 @@
* Returns zero on success, or a negative error code.
*/
int snd_fw_transaction(struct fw_unit *unit, int tcode,
- u64 offset, void *buffer, size_t length)
+ u64 offset, void *buffer, size_t length,
+ unsigned int flags)
{
struct fw_device *device = fw_parent_device(unit);
int generation, rcode, tries = 0;
+ generation = flags & FW_GENERATION_MASK;
for (;;) {
- generation = device->generation;
- smp_rmb(); /* node_id vs. generation */
+ if (!(flags & FW_FIXED_GENERATION)) {
+ generation = device->generation;
+ smp_rmb(); /* node_id vs. generation */
+ }
rcode = fw_run_transaction(device->card, tcode,
device->node_id, generation,
device->max_speed, offset,
@@ -43,9 +50,14 @@
if (rcode == RCODE_COMPLETE)
return 0;
+ if (rcode == RCODE_GENERATION && (flags & FW_FIXED_GENERATION))
+ return -EAGAIN;
+
if (rcode_is_permanent_error(rcode) || ++tries >= 3) {
- dev_err(&unit->device, "transaction failed: %s\n",
- fw_rcode_string(rcode));
+ if (!(flags & FW_QUIET))
+ dev_err(&unit->device,
+ "transaction failed: %s\n",
+ fw_rcode_string(rcode));
return -EIO;
}