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From: Finn Thain <fthain@telegraphics.com.au>
To: "James E.J. Bottomley" <JBottomley@odin.com>,
	"Martin K. Petersen" <martin.petersen@oracle.com>,
	Michael Schmitz <schmitzmic@gmail.com>,
	linux-m68k@vger.kernel.org, linux-scsi@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: [PATCH v4 38/78] ncr5380: Remove UNSAFE macro
Date: Sun, 03 Jan 2016 16:05:39 +1100	[thread overview]
Message-ID: <20160103050511.081776223@telegraphics.com.au> (raw)
In-Reply-To: 20160103050501.042035135@telegraphics.com.au

[-- Attachment #1: ncr5380-remove-UNSAFE-macro --]
[-- Type: text/plain, Size: 3367 bytes --]

Configuring core drivers using macros like this one prevents re-unifying
the core driver forks, and prevents implementing the core driver as a
library or a platform driver.

The UNSAFE macro in particular is a poor workaround for the problem of
interrupt latency. Releasing the locks complicates things because then we
would have to handle the possibility of EH handler invocation during a
PDMA transfer.

The comments say that instead of using this macro, "you're going to be
better off twiddling with transfersize". I agree. Remove this stuff.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Ondrej Zary <linux@rainbow-software.org>

---
 drivers/scsi/NCR5380.c |   15 ---------------
 drivers/scsi/dtc.c     |    2 --
 drivers/scsi/pas16.c   |    1 -
 3 files changed, 18 deletions(-)

Index: linux/drivers/scsi/NCR5380.c
===================================================================
--- linux.orig/drivers/scsi/NCR5380.c	2016-01-03 16:03:47.000000000 +1100
+++ linux/drivers/scsi/NCR5380.c	2016-01-03 16:03:49.000000000 +1100
@@ -195,12 +195,6 @@
  *      rely on phase mismatch and EOP interrupts to determine end 
  *      of phase.
  *
- * UNSAFE - leave interrupts enabled during pseudo-DMA transfers.  You
- *          only really want to use this if you're having a problem with
- *          dropped characters during high speed communications, and even
- *          then, you're going to be better off twiddling with transfersize
- *          in the high level code.
- *
  * Defaults for these will be provided although the user may want to adjust 
  * these to allocate CPU resources to the SCSI driver or "real" code.
  * 
@@ -554,9 +548,6 @@ static void prepare_info(struct Scsi_Hos
 #ifdef PSEUDO_DMA
 	         "PSEUDO_DMA "
 #endif
-#ifdef UNSAFE
-	         "UNSAFE "
-#endif
 	         "");
 }
 
@@ -1582,9 +1573,6 @@ static int NCR5380_transfer_dma(struct S
 	 * before the setting of DMA mode to after transfer of the last byte.
 	 */
 
-#if defined(PSEUDO_DMA) && defined(UNSAFE)
-	spin_unlock_irq(instance->host_lock);
-#endif
 	/* KLL May need eop and parity in 53c400 */
 	if (hostdata->flags & FLAG_NCR53C400)
 		NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE |
@@ -1793,9 +1781,6 @@ static int NCR5380_transfer_dma(struct S
 	*data = d + c;
 	*count = 0;
 	*phase = NCR5380_read(STATUS_REG) & PHASE_MASK;
-#if defined(PSEUDO_DMA) && defined(UNSAFE)
-	spin_lock_irq(instance->host_lock);
-#endif				/* defined(REAL_DMA_POLL) */
 	return foo;
 #endif				/* def REAL_DMA */
 }
Index: linux/drivers/scsi/dtc.c
===================================================================
--- linux.orig/drivers/scsi/dtc.c	2016-01-03 16:03:31.000000000 +1100
+++ linux/drivers/scsi/dtc.c	2016-01-03 16:03:49.000000000 +1100
@@ -1,7 +1,5 @@
-
 #define PSEUDO_DMA
 #define DONT_USE_INTR
-#define UNSAFE			/* Leave interrupts enabled during pseudo-dma I/O */
 #define DMA_WORKS_RIGHT
 
 
Index: linux/drivers/scsi/pas16.c
===================================================================
--- linux.orig/drivers/scsi/pas16.c	2016-01-03 16:03:23.000000000 +1100
+++ linux/drivers/scsi/pas16.c	2016-01-03 16:03:49.000000000 +1100
@@ -1,5 +1,4 @@
 #define PSEUDO_DMA
-#define UNSAFE  /* Not unsafe for PAS16 -- use it */
 
 /*
  * This driver adapted from Drew Eckhardt's Trantor T128 driver

  parent reply	other threads:[~2016-01-03  5:18 UTC|newest]

Thread overview: 94+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-01-03  5:05 [PATCH v4 00/78] More fixes, cleanup and modernization for NCR5380 drivers Finn Thain
2016-01-03  5:05 ` [PATCH v4 01/78] atari_scsi: Fix SCSI host ID setting Finn Thain
2016-01-03  5:05 ` [PATCH v4 02/78] ncr5380: Remove redundant static variable initializers Finn Thain
2016-01-03  5:05 ` [PATCH v4 03/78] ncr5380: Eliminate PDEBUG*, TDEBUG* and DTCDEBUG* macros Finn Thain
2016-01-03  5:05 ` [PATCH v4 04/78] ncr5380: Remove more pointless macros Finn Thain
2016-01-03  5:05 ` [PATCH v4 05/78] ncr5380: Remove NCR5380_local_declare and NCR5380_setup macros Finn Thain
2016-01-03  5:05 ` [PATCH v4 06/78] ncr5380: Remove NCR5380_instance_name macro Finn Thain
2016-01-03  5:05 ` [PATCH v4 07/78] ncr5380: Split NCR5380_init() into two functions Finn Thain
2016-01-03  5:05 ` [PATCH v4 08/78] ncr5380: Move NCR53C400-specific code Finn Thain
2016-01-03  5:05 ` [PATCH v4 09/78] atari_NCR5380: Reset bus on driver initialization if required Finn Thain
2016-01-03  5:05 ` [PATCH v4 10/78] atari_NCR5380: Remove RESET_BOOT, CONFIG_ATARI_SCSI_TOSHIBA_DELAY and CONFIG_ATARI_SCSI_RESET_BOOT Finn Thain
2016-01-03  5:05 ` [PATCH v4 11/78] ncr5380: Simplify bus reset handlers Finn Thain
2016-01-03  5:05 ` [PATCH v4 12/78] ncr5380: Remove unused hostdata->aborted flag Finn Thain
2016-01-03  5:05 ` [PATCH v4 13/78] ncr5380: Remove redundant register writes Finn Thain
2016-01-03  5:05 ` [PATCH v4 14/78] ncr5380: Use return instead of goto in NCR5380_select() Finn Thain
2016-01-03  5:05 ` [PATCH v4 15/78] ncr5380: Always escalate bad target time-out " Finn Thain
2016-01-03  5:05 ` [PATCH v4 16/78] ncr5380: Proceed with next command after NCR5380_select() calls scsi_done Finn Thain
2016-01-03  5:05 ` [PATCH v4 17/78] ncr5380: Keep BSY asserted when entering SELECTION phase Finn Thain
2016-01-03  5:05 ` [PATCH v4 18/78] ncr5380: Eliminate USLEEP_WAITLONG delay Finn Thain
2016-01-03  5:05 ` [PATCH v4 19/78] ncr5380: Cleanup bogus {request, release}_region() calls Finn Thain
2016-01-03  5:05 ` [PATCH v4 20/78] ncr5380: Introduce unbound workqueue Finn Thain
2016-01-03  5:05 ` [PATCH v4 21/78] ncr5380: Sleep when polling, if possible Finn Thain
2016-01-03  5:05 ` [PATCH v4 22/78] ncr5380: Eliminate selecting state Finn Thain
2016-01-03  5:05 ` [PATCH v4 23/78] ncr5380: Always retry arbitration and selection Finn Thain
2016-01-03  5:05 ` [PATCH v4 24/78] ncr5380: Implement NCR5380_dma_xfer_len and remove LIMIT_TRANSFERSIZE macro Finn Thain
2016-01-03  5:05 ` [PATCH v4 25/78] ncr5380: Rework disconnect versus poll logic Finn Thain
2016-01-03  5:05 ` [PATCH v4 26/78] ncr5380: Fix NCR5380_transfer_pio() result Finn Thain
2016-01-03  5:05 ` [PATCH v4 27/78] ncr5380: Add missing lock in eh_abort_handler Finn Thain
2016-01-03  5:05 ` [PATCH v4 28/78] ncr5380: Drop DEF_SCSI_QCMD macro Finn Thain
2016-01-03  5:05 ` [PATCH v4 29/78] ncr5380: Remove references to linked commands Finn Thain
2016-01-03  5:05 ` [PATCH v4 30/78] ncr5380: Add missing break after case MESSAGE_REJECT Finn Thain
2016-01-03  5:05 ` [PATCH v4 31/78] ncr5380: Fix !REQ timeout in do_abort() Finn Thain
2016-01-03  5:05 ` [PATCH v4 32/78] ncr5380: Fix bus phase " Finn Thain
2016-01-03  5:05 ` [PATCH v4 33/78] atari_NCR5380: Set do_abort() timeouts Finn Thain
2016-01-03  5:05 ` [PATCH v4 34/78] atari_NCR5380: Use arbitration timeout Finn Thain
2016-01-24 10:38   ` Geert Uytterhoeven
2016-01-25  2:45     ` Finn Thain
2016-01-25  8:05       ` Geert Uytterhoeven
2016-01-25 18:28         ` Andreas Schwab
2016-01-25 19:56         ` Michael Schmitz
2016-01-26  0:18         ` Finn Thain
2016-01-26 11:13           ` Geert Uytterhoeven
2016-01-03  5:05 ` [PATCH v4 35/78] ncr5380: Dont wait for BUS FREE after disconnect Finn Thain
2016-01-03  5:05 ` [PATCH v4 36/78] ncr5380: Use work_struct instead of delayed_work Finn Thain
2016-01-03  5:05 ` [PATCH v4 37/78] ncr5380: Standardize work queueing algorithm Finn Thain
2016-01-03  5:05 ` Finn Thain [this message]
2016-01-03  5:05 ` [PATCH v4 39/78] ncr5380: Standardize interrupt handling Finn Thain
2016-01-03  5:05 ` [PATCH v4 40/78] ncr5380: Introduce NCR5380_poll_politely2 Finn Thain
2016-01-03  5:05 ` [PATCH v4 41/78] ncr5380: Replace redundant flags with FLAG_NO_DMA_FIXUP Finn Thain
2016-01-03  5:05 ` [PATCH v4 42/78] ncr5380: Replace READ_OVERRUNS macro with FLAG_NO_DMA_FIXUPS Finn Thain
2016-01-03  5:05 ` [PATCH v4 43/78] ncr5380: Standardize reselection handling Finn Thain
2016-01-03  5:05 ` [PATCH v4 44/78] ncr5380: Fix off-by-one bug in extended_msg[] bounds check Finn Thain
2016-01-03  5:05 ` [PATCH v4 45/78] ncr5380: Cleanup #include directives Finn Thain
2016-01-03  5:05 ` [PATCH v4 46/78] ncr5380: Fix NDEBUG_NO_DATAOUT flag Finn Thain
2016-01-03  5:05 ` [PATCH v4 47/78] ncr5380: Fix and cleanup scsi_host_template initializers Finn Thain
2016-01-03  5:05 ` [PATCH v4 48/78] atari_NCR5380: Fix queue_size limit Finn Thain
2016-01-03  5:05 ` [PATCH v4 49/78] ncr5380: Remove redundant ICR_ARBITRATION_LOST test and eliminate FLAG_DTC3181E Finn Thain
2016-01-03  5:05 ` [PATCH v4 50/78] ncr5380: Change instance->host_lock to hostdata->lock Finn Thain
2016-01-03  5:05 ` [PATCH v4 51/78] ncr5380: Remove command list debug code Finn Thain
2016-01-03  5:05 ` [PATCH v4 52/78] ncr5380: Remove H_NO macro and introduce dsprintk Finn Thain
2016-01-03  5:05 ` [PATCH v4 53/78] ncr5380: Use shost_priv helper Finn Thain
2016-01-03  5:05 ` [PATCH v4 54/78] ncr5380: Use dsprintk() for queue debugging Finn Thain
2016-01-03  5:05 ` [PATCH v4 55/78] ncr5380: Remove LIST and REMOVE macros Finn Thain
2016-01-03  5:05 ` [PATCH v4 56/78] ncr5380: Remove redundant volatile qualifiers Finn Thain
2016-01-03  5:05 ` [PATCH v4 57/78] ncr5380: Use standard list data structure Finn Thain
2016-01-03  5:05 ` [PATCH v4 58/78] ncr5380: Refactor command completion Finn Thain
2016-01-03  5:06 ` [PATCH v4 59/78] ncr5380: Fix autosense bugs Finn Thain
2016-01-03  5:06 ` [PATCH v4 60/78] ncr5380: Implement new eh_abort_handler Finn Thain
2016-01-03  5:06 ` [PATCH v4 61/78] ncr5380: Fix EH during arbitration and selection Finn Thain
2016-01-03  5:06 ` [PATCH v4 62/78] ncr5380: Implement new eh_bus_reset_handler Finn Thain
2016-01-03  5:06 ` [PATCH v4 63/78] atari_NCR5380: Remove HOSTNO macro from printk() and seq_printf() calls Finn Thain
2016-01-03  5:06 ` [PATCH v4 64/78] atari_NCR5380: Eliminate HOSTNO macro Finn Thain
2016-01-03  5:06 ` [PATCH v4 65/78] atari_scsi, sun3_scsi: Remove global Scsi_Host pointer Finn Thain
2016-01-03  5:06 ` [PATCH v4 66/78] ncr5380: Fix soft lockups Finn Thain
2016-01-03  5:06 ` [PATCH v4 67/78] ncr5380: Cleanup comments Finn Thain
2016-01-03  5:06 ` [PATCH v4 68/78] ncr5380: Fix trailing whitespace using regexp Finn Thain
2016-01-03  5:06 ` [PATCH v4 69/78] ncr5380: Fix whitespace in comments " Finn Thain
2016-01-03  7:54   ` Joe Perches
2016-01-03  8:17     ` Finn Thain
2016-01-03 14:10     ` One Thousand Gnomes
2016-01-03 18:20       ` Joe Perches
2016-01-03 21:29         ` One Thousand Gnomes
2016-01-03 21:46           ` Joe Perches
     [not found]             ` <20160103220505.7734a879@lxorguk.ukuu.org.uk>
2016-01-03 22:13               ` Joe Perches
2016-01-03  5:06 ` [PATCH v4 70/78] ncr5380: Merge changes from atari_NCR5380.c Finn Thain
2016-01-03  5:06 ` [PATCH v4 71/78] atari_NCR5380: Merge changes from NCR5380.c Finn Thain
2016-01-03  5:06 ` [PATCH v4 72/78] ncr5380: Cleanup whitespace and parentheses Finn Thain
2016-01-03  5:06 ` [PATCH v4 73/78] ncr5380: Fix pseudo DMA transfers on 53C400 Finn Thain
2016-01-03  5:06 ` [PATCH v4 74/78] ncr5380: Use runtime register mapping Finn Thain
2016-01-03  5:06 ` [PATCH v4 75/78] ncr5380: Enable PDMA for NCR53C400A Finn Thain
2016-01-03  5:06 ` [PATCH v4 76/78] ncr5380: Enable PDMA for DTC chips Finn Thain
2016-01-03  5:06 ` [PATCH v4 77/78] ncr5380: Fix wait for 53C80 registers registers after PDMA Finn Thain
2016-01-03  5:06 ` [PATCH v4 78/78] ncr5380: Add support for HP C2502 Finn Thain
2016-01-07  2:53 ` [PATCH v4 00/78] More fixes, cleanup and modernization for NCR5380 drivers Martin K. Petersen

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