mirror of
https://github.com/torvalds/linux.git
synced 2024-11-27 22:51:35 +00:00
1b70485f13
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>
72 lines
2.1 KiB
C
72 lines
2.1 KiB
C
/*
|
|
* miscellaneous helper functions
|
|
*
|
|
* Copyright (c) Clemens Ladisch <clemens@ladisch.de>
|
|
* Licensed under the terms of the GNU General Public License, version 2.
|
|
*/
|
|
|
|
#include <linux/delay.h>
|
|
#include <linux/device.h>
|
|
#include <linux/firewire.h>
|
|
#include <linux/module.h>
|
|
#include "lib.h"
|
|
|
|
#define ERROR_RETRY_DELAY_MS 20
|
|
|
|
/**
|
|
* snd_fw_transaction - send a request and wait for its completion
|
|
* @unit: the driver's unit on the target device
|
|
* @tcode: the transaction code
|
|
* @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.
|
|
* On a bus reset or an error, the transaction is retried a few times.
|
|
* 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,
|
|
unsigned int flags)
|
|
{
|
|
struct fw_device *device = fw_parent_device(unit);
|
|
int generation, rcode, tries = 0;
|
|
|
|
generation = flags & FW_GENERATION_MASK;
|
|
for (;;) {
|
|
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,
|
|
buffer, length);
|
|
|
|
if (rcode == RCODE_COMPLETE)
|
|
return 0;
|
|
|
|
if (rcode == RCODE_GENERATION && (flags & FW_FIXED_GENERATION))
|
|
return -EAGAIN;
|
|
|
|
if (rcode_is_permanent_error(rcode) || ++tries >= 3) {
|
|
if (!(flags & FW_QUIET))
|
|
dev_err(&unit->device,
|
|
"transaction failed: %s\n",
|
|
fw_rcode_string(rcode));
|
|
return -EIO;
|
|
}
|
|
|
|
msleep(ERROR_RETRY_DELAY_MS);
|
|
}
|
|
}
|
|
EXPORT_SYMBOL(snd_fw_transaction);
|
|
|
|
MODULE_DESCRIPTION("FireWire audio helper functions");
|
|
MODULE_AUTHOR("Clemens Ladisch <clemens@ladisch.de>");
|
|
MODULE_LICENSE("GPL v2");
|