scsi: core: Clean up SG_NONE

Remove SG_NONE and a related misleading comment. Update documentation.

This patch does not affect behaviour as zero initialization is redundant.

Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Viresh Kumar <vireshk@kernel.org>
Cc: Oliver Neukum <oneukum@suse.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: usb-storage@lists.one-eyed-alien.net
Link: https://lore.kernel.org/r/b4779b7a6563f6bd8d259ee457871c1c463c420e.1572656814.git.fthain@telegraphics.com.au
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This commit is contained in:
Finn Thain 2019-11-02 12:06:54 +11:00 committed by Martin K. Petersen
parent 79172ab20b
commit 35c3363363
5 changed files with 3 additions and 17 deletions

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@ -1084,7 +1084,8 @@ of interest:
commands to the adapter.
this_id - scsi id of host (scsi initiator) or -1 if not known
sg_tablesize - maximum scatter gather elements allowed by host.
0 implies scatter gather not supported by host
Set this to SG_ALL or less to avoid chained SG lists.
Must be at least 1.
max_sectors - maximum number of sectors (usually 512 bytes) allowed
in a single SCSI command. The default value of 0 leads
to a setting of SCSI_DEFAULT_MAX_SECTORS (defined in

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@ -219,7 +219,6 @@ struct arasan_cf_dev {
static struct scsi_host_template arasan_cf_sht = {
ATA_BASE_SHT(DRIVER_NAME),
.sg_tablesize = SG_NONE,
.dma_boundary = 0xFFFFFFFFUL,
};

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@ -1680,7 +1680,7 @@ static struct scsi_host_template atp870u_template = {
.bios_param = atp870u_biosparam /* biosparm */,
.can_queue = qcnt /* can_queue */,
.this_id = 7 /* SCSI ID */,
.sg_tablesize = ATP870U_SCATTER /*SG_ALL*/ /*SG_NONE*/,
.sg_tablesize = ATP870U_SCATTER /*SG_ALL*/,
.max_sectors = ATP870U_MAX_SECTORS,
};

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@ -879,7 +879,6 @@ static struct scsi_host_template uas_host_template = {
.eh_abort_handler = uas_eh_abort_handler,
.eh_device_reset_handler = uas_eh_device_reset_handler,
.this_id = -1,
.sg_tablesize = SG_NONE,
.skip_settle_delay = 1,
.dma_boundary = PAGE_SIZE - 1,
};

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@ -23,19 +23,6 @@ struct scsi_host_cmd_pool;
struct scsi_transport_template;
/*
* The various choices mean:
* NONE: Self evident. Host adapter is not capable of scatter-gather.
* ALL: Means that the host adapter module can do scatter-gather,
* and that there is no limit to the size of the table to which
* we scatter/gather data. The value we set here is the maximum
* single element sglist. To use chained sglists, the adapter
* has to set a value beyond ALL (and correctly use the chain
* handling API.
* Anything else: Indicates the maximum number of chains that can be
* used in one scatter-gather request.
*/
#define SG_NONE 0
#define SG_ALL SG_CHUNK_SIZE
#define MODE_UNKNOWN 0x00