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Subject[PATCH] ide-cd: remove obsolete seek optimization
Date
It doesn't make much sense nowadays and is problematic on some drives.

Cc: Borislav Petkov <petkovbb@googlemail.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
---
against pata tree

drivers/ide/ide-cd.c | 89 +++------------------------------------------------
drivers/ide/ide-cd.h | 2 -
include/linux/ide.h | 4 --
3 files changed, 6 insertions(+), 89 deletions(-)

Index: b/drivers/ide/ide-cd.c
===================================================================
--- a/drivers/ide/ide-cd.c
+++ b/drivers/ide/ide-cd.c
@@ -774,52 +774,6 @@ static ide_startstop_t cdrom_start_rw_co
return cdrom_transfer_packet_command(drive, rq, cdrom_newpc_intr);
}

-#define IDECD_SEEK_THRESHOLD (1000) /* 1000 blocks */
-#define IDECD_SEEK_TIMER (5 * WAIT_MIN_SLEEP) /* 100 ms */
-#define IDECD_SEEK_TIMEOUT (2 * WAIT_CMD) /* 20 sec */
-
-static ide_startstop_t cdrom_seek_intr(ide_drive_t *drive)
-{
- struct cdrom_info *info = drive->driver_data;
- int stat;
- static int retry = 10;
-
- ide_debug_log(IDE_DBG_FUNC, "Call %s\n", __func__);
-
- if (cdrom_decode_status(drive, 0, &stat))
- return ide_stopped;
-
- drive->atapi_flags |= IDE_AFLAG_SEEKING;
-
- if (retry && time_after(jiffies, info->start_seek + IDECD_SEEK_TIMER)) {
- if (--retry == 0)
- drive->dev_flags &= ~IDE_DFLAG_DSC_OVERLAP;
- }
- return ide_stopped;
-}
-
-static void ide_cd_prepare_seek_request(ide_drive_t *drive, struct request *rq)
-{
- sector_t frame = rq->sector;
-
- ide_debug_log(IDE_DBG_FUNC, "Call %s\n", __func__);
-
- sector_div(frame, queue_hardsect_size(drive->queue) >> SECTOR_BITS);
-
- memset(rq->cmd, 0, BLK_MAX_CDB);
- rq->cmd[0] = GPCMD_SEEK;
- put_unaligned(cpu_to_be32(frame), (unsigned int *) &rq->cmd[2]);
-
- rq->timeout = ATAPI_WAIT_PC;
-}
-
-static ide_startstop_t cdrom_start_seek_continuation(ide_drive_t *drive)
-{
- struct request *rq = drive->hwif->hwgroup->rq;
-
- return cdrom_transfer_packet_command(drive, rq, &cdrom_seek_intr);
-}
-
/*
* Fix up a possibly partially-processed request so that we can start it over
* entirely, or even put it back on the request queue.
@@ -1259,7 +1213,6 @@ static void cdrom_do_block_pc(ide_drive_
static ide_startstop_t ide_cd_do_request(ide_drive_t *drive, struct request *rq,
sector_t block)
{
- struct cdrom_info *info = drive->driver_data;
ide_handler_t *fn;
int xferlen;

@@ -1269,44 +1222,14 @@ static ide_startstop_t ide_cd_do_request
(unsigned long long)block);

if (blk_fs_request(rq)) {
- if (drive->atapi_flags & IDE_AFLAG_SEEKING) {
- ide_hwif_t *hwif = drive->hwif;
- unsigned long elapsed = jiffies - info->start_seek;
- int stat = hwif->tp_ops->read_status(hwif);
-
- if ((stat & ATA_DSC) != ATA_DSC) {
- if (elapsed < IDECD_SEEK_TIMEOUT) {
- ide_stall_queue(drive,
- IDECD_SEEK_TIMER);
- return ide_stopped;
- }
- printk(KERN_ERR PFX "%s: DSC timeout\n",
- drive->name);
- }
- drive->atapi_flags &= ~IDE_AFLAG_SEEKING;
- }
- if (rq_data_dir(rq) == READ &&
- IDE_LARGE_SEEK(info->last_block, block,
- IDECD_SEEK_THRESHOLD) &&
- (drive->dev_flags & IDE_DFLAG_DSC_OVERLAP)) {
- xferlen = 0;
- fn = cdrom_start_seek_continuation;
-
- drive->dma = 0;
- info->start_seek = jiffies;
-
- ide_cd_prepare_seek_request(drive, rq);
- } else {
- xferlen = 32768;
- fn = cdrom_start_rw_cont;
+ xferlen = 32768;
+ fn = cdrom_start_rw_cont;

- if (cdrom_start_rw(drive, rq) == ide_stopped)
- return ide_stopped;
+ if (cdrom_start_rw(drive, rq) == ide_stopped)
+ return ide_stopped;

- if (ide_cd_prepare_rw_request(drive, rq) == ide_stopped)
- return ide_stopped;
- }
- info->last_block = block;
+ if (ide_cd_prepare_rw_request(drive, rq) == ide_stopped)
+ return ide_stopped;
} else if (blk_sense_request(rq) || blk_pc_request(rq) ||
rq->cmd_type == REQ_TYPE_ATA_PC) {
xferlen = rq->data_len;
Index: b/drivers/ide/ide-cd.h
===================================================================
--- a/drivers/ide/ide-cd.h
+++ b/drivers/ide/ide-cd.h
@@ -88,8 +88,6 @@ struct cdrom_info {
struct request_sense sense_data;

struct request request_sense_request;
- unsigned long last_block;
- unsigned long start_seek;

u8 max_speed; /* Max speed of the drive. */
u8 current_speed; /* Current speed of the drive. */
Index: b/include/linux/ide.h
===================================================================
--- a/include/linux/ide.h
+++ b/include/linux/ide.h
@@ -122,8 +122,6 @@ struct ide_io_ports {
#define MAX_DRIVES 2 /* per interface; 2 assumed by lots of code */
#define SECTOR_SIZE 512

-#define IDE_LARGE_SEEK(b1,b2,t) (((b1) > (b2) + (t)) || ((b2) > (b1) + (t)))
-
/*
* Timeouts for various operations:
*/
@@ -496,8 +494,6 @@ enum {
* when more than one interrupt is needed.
*/
IDE_AFLAG_LIMIT_NFRAMES = (1 << 7),
- /* Seeking in progress. */
- IDE_AFLAG_SEEKING = (1 << 8),
/* Saved TOC information is current. */
IDE_AFLAG_TOC_VALID = (1 << 9),
/* We think that the drive door is locked. */

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