ide-{floppy,tape}: remove packet command stack

[linux-2.6-omap-h63xx.git] / drivers / ide / ide-tape.c

diff --git a/drivers/ide/ide-tape.c b/drivers/ide/ide-tape.c
index dd3533505e3b57ef40d73b9d49ab8b54887fc31c..ba05e03f482bed8cd33b6f4080ec83f55a3e3c3c 100644 (file)
--- a/drivers/ide/ide-tape.c
+++ b/drivers/ide/ide-tape.c
@@ -56,8 +56,6 @@ enum {
        DBG_CHRDEV =            (1 << 2),
        /* all remaining procedures */
        DBG_PROCS =             (1 << 3),
-       /* buffer alloc info (pc_stack) */
-       DBG_PC_STACK =  (1 << 4),
 };
 
 /* define to see debug info */
@@ -88,13 +86,6 @@ enum {
  */
 #define IDETAPE_PC_BUFFER_SIZE         256
 
-/*
- * In various places in the driver, we need to allocate storage for packet
- * commands, which will remain valid while we leave the driver to wait for
- * an interrupt or a timeout event.
- */
-#define IDETAPE_PC_STACK               (10 + IDETAPE_MAX_PC_RETRIES)
-
 /*
  * Some drives (for example, Seagate STT3401A Travan) require a very long
  * timeout, because they don't return an interrupt or clear their busy bit
@@ -208,13 +199,6 @@ typedef struct ide_tape_obj {
        struct kref     kref;
 
        /*
-        *      Since a typical character device operation requires more
-        *      than one packet command, we provide here enough memory
-        *      for the maximum of interconnected packet commands.
-        *      The packet commands are stored in the circular array pc_stack.
-        *      pc_stack_index points to the last used entry, and warps around
-        *      to the start when we get to the last array entry.
-        *
         *      pc points to the current processed packet command.
         *
         *      failed_pc points to the last failed packet command, or contains
@@ -226,11 +210,10 @@ typedef struct ide_tape_obj {
        struct ide_atapi_pc *pc;
        /* Last failed packet command */
        struct ide_atapi_pc *failed_pc;
-       /* Packet command stack */
-       struct ide_atapi_pc pc_stack[IDETAPE_PC_STACK];
-       /* Next free packet command storage space */
-       int pc_stack_index;
+       /* used by REQ_IDETAPE_{READ,WRITE} requests */
+       struct ide_atapi_pc queued_pc;
 
+       struct ide_atapi_pc request_sense_pc;
        struct request request_sense_rq;
 
        /*
@@ -451,23 +434,6 @@ static void idetape_update_buffers(ide_drive_t *drive, struct ide_atapi_pc *pc)
        pc->bh = bh;
 }
 
-/*
- *     idetape_next_pc_storage returns a pointer to a place in which we can
- *     safely store a packet command, even though we intend to leave the
- *     driver. A storage space for a maximum of IDETAPE_PC_STACK packet
- *     commands is allocated at initialization time.
- */
-static struct ide_atapi_pc *idetape_next_pc_storage(ide_drive_t *drive)
-{
-       idetape_tape_t *tape = drive->driver_data;
-
-       debug_log(DBG_PC_STACK, "pc_stack_index=%d\n", tape->pc_stack_index);
-
-       if (tape->pc_stack_index == IDETAPE_PC_STACK)
-               tape->pc_stack_index = 0;
-       return (&tape->pc_stack[tape->pc_stack_index++]);
-}
-
 /*
  * called on each failed packet command retry to analyze the request sense. We
  * currently do not utilize this information.
@@ -693,10 +659,9 @@ static void idetape_retry_pc(ide_drive_t *drive)
 {
        struct ide_tape_obj *tape = drive->driver_data;
        struct request *rq = &tape->request_sense_rq;
-       struct ide_atapi_pc *pc;
+       struct ide_atapi_pc *pc = &tape->request_sense_pc;
 
        (void)ide_read_error(drive);
-       pc = idetape_next_pc_storage(drive);
        idetape_create_request_sense_cmd(pc);
        set_bit(IDE_AFLAG_IGNORE_DSC, &drive->atapi_flags);
        idetape_queue_pc_head(drive, pc, rq);
@@ -1006,12 +971,12 @@ static ide_startstop_t idetape_do_request(ide_drive_t *drive,
                return ide_stopped;
        }
        if (rq->cmd[13] & REQ_IDETAPE_READ) {
-               pc = idetape_next_pc_storage(drive);
+               pc = &tape->queued_pc;
                ide_tape_create_rw_cmd(tape, pc, rq, READ_6);
                goto out;
        }
        if (rq->cmd[13] & REQ_IDETAPE_WRITE) {
-               pc = idetape_next_pc_storage(drive);
+               pc = &tape->queued_pc;
                ide_tape_create_rw_cmd(tape, pc, rq, WRITE_6);
                goto out;
        }
@@ -2412,7 +2377,6 @@ static void idetape_setup(ide_drive_t *drive, idetape_tape_t *tape, int minor)
        tape->name[1] = 't';
        tape->name[2] = '0' + minor;
        tape->chrdev_dir = IDETAPE_DIR_NONE;
-       tape->pc = tape->pc_stack;
 
        *((u16 *)&gcw) = drive->id[ATA_ID_CONFIG];