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Message-ID: <1401435950.6101.6.camel@x220>
Date: Fri, 30 May 2014 09:45:50 +0200
From: Paul Bolle <pebolle@...cali.nl>
To: "James E.J. Bottomley" <JBottomley@...allels.com>,
Randy Dunlap <rdunlap@...radead.org>
Cc: linux-scsi@...r.kernel.org, linux-doc@...r.kernel.org,
linux-kernel@...r.kernel.org
Subject: [PATCH] ncr53c8xx: remove remnants of immediate arbitration
The code for immediate arbitration was removed from (what looks like a
predecessor of) the ncr53c8xx code in v2.6.0. Remove its remnants now.
Signed-off-by: Paul Bolle <pebolle@...cali.nl>
---
Untested.
Documentation/scsi/ncr53c8xx.txt | 52 ----------------------------------------
drivers/scsi/ncr53c8xx.c | 12 ----------
drivers/scsi/ncr53c8xx.h | 8 -------
3 files changed, 72 deletions(-)
diff --git a/Documentation/scsi/ncr53c8xx.txt b/Documentation/scsi/ncr53c8xx.txt
index 1d508dcbf859..49c7b723225b 100644
--- a/Documentation/scsi/ncr53c8xx.txt
+++ b/Documentation/scsi/ncr53c8xx.txt
@@ -52,12 +52,10 @@ Written by Gerard Roudier <groudier@...e.fr>
10.2.19 Check SCSI BUS
10.2.20 Exclude a host from being attached
10.2.21 Suggest a default SCSI id for hosts
- 10.2.22 Enable use of IMMEDIATE ARBITRATION
10.3 Advised boot setup commands
10.4 PCI configuration fix-up boot option
10.5 Serial NVRAM support boot option
10.6 SCSI BUS checking boot option
- 10.7 IMMEDIATE ARBITRATION boot option
11. Some constants and flags of the ncr53c8xx.h header file
12. Installation
13. Architecture dependent features
@@ -843,16 +841,6 @@ port address 0x1400.
try to deduce the value previously set in the hardware and use value
7 if the hardware value is zero.
-10.2.22 Enable use of IMMEDIATE ARBITRATION
- (only supported by the sym53c8xx driver. See 10.7 for more details)
- iarb:0 do not use this feature.
- iarb:#x use this feature according to bit fields as follow:
-
- bit 0 (1) : enable IARB each time the initiator has been reselected
- when it arbitrated for the SCSI BUS.
- (#x >> 4) : maximum number of successive settings of IARB if the initiator
- win arbitration and it has other commands to send to a device.
-
Boot fail safe
safe:y load the following assumed fail safe initial setup
@@ -876,7 +864,6 @@ Boot fail safe
differential support from BIOS settings diff:1
irq mode from BIOS settings irqm:1
SCSI BUS check do not attach on error buschk:1
- immediate arbitration disabled iarb:0
10.3 Advised boot setup commands
@@ -1005,45 +992,6 @@ Unfortunately, the following common SCSI BUS problems are not detected:
On the other hand, either bad cabling, broken devices, not conformant
devices, ... may cause a SCSI signal to be wrong when te driver reads it.
-10.7 IMMEDIATE ARBITRATION boot option
-
-This option is only supported by the SYM53C8XX driver (not by the NCR53C8XX).
-
-SYMBIOS 53C8XX chips are able to arbitrate for the SCSI BUS as soon as they
-have detected an expected disconnection (BUS FREE PHASE). For this process
-to be started, bit 1 of SCNTL1 IO register must be set when the chip is
-connected to the SCSI BUS.
-
-When this feature has been enabled for the current connection, the chip has
-every chance to win arbitration if only devices with lower priority are
-competing for the SCSI BUS. By the way, when the chip is using SCSI id 7,
-then it will for sure win the next SCSI BUS arbitration.
-
-Since, there is no way to know what devices are trying to arbitrate for the
-BUS, using this feature can be extremely unfair. So, you are not advised
-to enable it, or at most enable this feature for the case the chip lost
-the previous arbitration (boot option 'iarb:1').
-
-This feature has the following advantages:
-
-a) Allow the initiator with ID 7 to win arbitration when it wants so.
-b) Overlap at least 4 micro-seconds of arbitration time with the execution
- of SCRIPTS that deal with the end of the current connection and that
- starts the next job.
-
-Hmmm... But (a) may just prevent other devices from reselecting the initiator,
-and delay data transfers or status/completions, and (b) may just waste
-SCSI BUS bandwidth if the SCRIPTS execution lasts more than 4 micro-seconds.
-
-The use of IARB needs the SCSI_NCR_IARB_SUPPORT option to have been defined
-at compile time and the 'iarb' boot option to have been set to a non zero
-value at boot time. It is not that useful for real work, but can be used
-to stress SCSI devices or for some applications that can gain advantage of
-it. By the way, if you experience badnesses like 'unexpected disconnections',
-'bad reselections', etc... when using IARB on heavy IO load, you should not
-be surprised, because force-feeding anything and blocking its arse at the
-same time cannot work for a long time. :-))
-
11. Some constants and flags of the ncr53c8xx.h header file
diff --git a/drivers/scsi/ncr53c8xx.c b/drivers/scsi/ncr53c8xx.c
index 7d014b11df62..9661a2c9e13c 100644
--- a/drivers/scsi/ncr53c8xx.c
+++ b/drivers/scsi/ncr53c8xx.c
@@ -615,10 +615,6 @@ static struct ncr_driver_setup
#define OPT_EXCLUDE 24
#define OPT_HOST_ID 25
-#ifdef SCSI_NCR_IARB_SUPPORT
-#define OPT_IARB 26
-#endif
-
#ifdef MODULE
#define ARG_SEP ' '
#else
@@ -640,9 +636,6 @@ static char setup_token[] __initdata =
"recovery:"
"safe:" "nvram:"
"excl:" "hostid:"
-#ifdef SCSI_NCR_IARB_SUPPORT
- "iarb:"
-#endif
; /* DONNOT REMOVE THIS ';' */
static int __init get_setup_token(char *p)
@@ -766,11 +759,6 @@ static int __init sym53c8xx__setup(char *str)
case OPT_HOST_ID:
driver_setup.host_id = val;
break;
-#ifdef SCSI_NCR_IARB_SUPPORT
- case OPT_IARB:
- driver_setup.iarb = val;
- break;
-#endif
default:
printk("sym53c8xx_setup: unexpected boot option '%.*s' ignored\n", (int)(pc-cur+1), cur);
break;
diff --git a/drivers/scsi/ncr53c8xx.h b/drivers/scsi/ncr53c8xx.h
index 736a9df68d58..e34ec5a2ea5e 100644
--- a/drivers/scsi/ncr53c8xx.h
+++ b/drivers/scsi/ncr53c8xx.h
@@ -112,13 +112,6 @@
#endif
/*
- * Immediate arbitration
- */
-#if defined(CONFIG_SCSI_NCR53C8XX_IARB)
-#define SCSI_NCR_IARB_SUPPORT
-#endif
-
-/*
* Sync transfer frequency at startup.
* Allow from 5Mhz to 80Mhz default 20 Mhz.
*/
@@ -534,7 +527,6 @@ struct ncr_driver_setup {
u8 optimize;
u8 recovery;
u8 host_id;
- u16 iarb;
u32 excludes[SCSI_NCR_MAX_EXCLUDES];
char tag_ctrl[100];
};
--
1.9.3
--
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