lib.c

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/*
 * miscellaneous helper functions
 *
 * Copyright (c) Clemens Ladisch <[email protected]>
 * 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    5

int snd_fw_transaction(struct fw_unit *unit, int tcode,
               u64 offset, void *buffer, size_t length)
{
    struct fw_device *device = fw_parent_device(unit);
    int generation, rcode, tries = 0;

    for (;;) {
        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_is_permanent_error(rcode) || ++tries >= 3) {
            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 <[email protected]>");
MODULE_LICENSE("GPL v2");