libata: make reset related methods proper port operations

Currently reset methods are not specified directly in the
ata_port_operations table.  If a LLD wants to use custom reset
methods, it should construct and use a error_handler which uses those
reset methods.  It's done this way for two reasons.

First, the ops table already contained too many methods and adding
four more of them would noticeably increase the amount of necessary
boilerplate code all over low level drivers.

Second, as ->error_handler uses those reset methods, it can get
confusing.  ie. By overriding ->error_handler, those reset ops can be
made useless making layering a bit hazy.

Now that ops table uses inheritance, the first problem doesn't exist
anymore.  The second isn't completely solved but is relieved by
providing default values - most drivers can just override what it has
implemented and don't have to concern itself about higher level
callbacks.  In fact, there currently is no driver which actually
modifies error handling behavior.  Drivers which override
->error_handler just wraps the standard error handler only to prepare
the controller for EH.  I don't think making ops layering strict has
any noticeable benefit.

This patch makes ->prereset, ->softreset, ->hardreset, ->postreset and
their PMP counterparts propoer ops.  Default ops are provided in the
base ops tables and drivers are converted to override individual reset
methods instead of creating custom error_handler.

* ata_std_error_handler() doesn't use sata_std_hardreset() if SCRs
  aren't accessible.  sata_promise doesn't need to use separate
  error_handlers for PATA and SATA anymore.

* softreset is broken for sata_inic162x and sata_sx4.  As libata now
  always prefers hardreset, this doesn't really matter but the ops are
  forced to NULL using ATA_OP_NULL for documentation purpose.

* pata_hpt374 needs to use different prereset for the first and second
  PCI functions.  This used to be done by branching from
  hpt374_error_handler().  The proper way to do this is to use
  separate ops and port_info tables for each function.  Converted.

Signed-off-by: Tejun Heo <htejun@gmail.com>

1 files changed, 5 insertions, 12 deletions

diff --git a/drivers/ata/sata_nv.c b/drivers/ata/sata_nv.c
index 5637b082bc85..b2eb5724cf85 100644
--- a/drivers/ata/sata_nv.c
+++ b/drivers/ata/sata_nv.c
@@ -309,7 +309,8 @@ static void nv_nf2_freeze(struct ata_port *ap);
 static void nv_nf2_thaw(struct ata_port *ap);
 static void nv_ck804_freeze(struct ata_port *ap);
 static void nv_ck804_thaw(struct ata_port *ap);
-static void nv_error_handler(struct ata_port *ap);
+static int nv_hardreset(struct ata_link *link, unsigned int *class,
+			unsigned long deadline);
 static int nv_adma_slave_config(struct scsi_device *sdev);
 static int nv_adma_check_atapi_dma(struct ata_queued_cmd *qc);
 static void nv_adma_qc_prep(struct ata_queued_cmd *qc);
@@ -406,7 +407,7 @@ static struct scsi_host_template nv_swncq_sht = {
 
 static struct ata_port_operations nv_generic_ops = {
 	.inherits		= &ata_bmdma_port_ops,
-	.error_handler		= nv_error_handler,
+	.hardreset		= nv_hardreset,
 	.scr_read		= nv_scr_read,
 	.scr_write		= nv_scr_write,
 };
@@ -1599,12 +1600,6 @@ static int nv_hardreset(struct ata_link *link, unsigned int *class,
 	return sata_std_hardreset(link, &dummy, deadline);
 }
 
-static void nv_error_handler(struct ata_port *ap)
-{
-	ata_bmdma_drive_eh(ap, ata_std_prereset, ata_std_softreset,
-			   nv_hardreset, ata_std_postreset);
-}
-
 static void nv_adma_error_handler(struct ata_port *ap)
 {
 	struct nv_adma_port_priv *pp = ap->private_data;
@@ -1658,8 +1653,7 @@ static void nv_adma_error_handler(struct ata_port *ap)
 		readw(mmio + NV_ADMA_CTL);	/* flush posted write */
 	}
 
-	ata_bmdma_drive_eh(ap, ata_std_prereset, ata_std_softreset,
-			   nv_hardreset, ata_std_postreset);
+	ata_bmdma_error_handler(ap);
 }
 
 static void nv_swncq_qc_to_dq(struct ata_port *ap, struct ata_queued_cmd *qc)
@@ -1785,8 +1779,7 @@ static void nv_swncq_error_handler(struct ata_port *ap)
 		ehc->i.action |= ATA_EH_RESET;
 	}
 
-	ata_bmdma_drive_eh(ap, ata_std_prereset, ata_std_softreset,
-			   nv_hardreset, ata_std_postreset);
+	ata_bmdma_error_handler(ap);
 }
 
 #ifdef CONFIG_PM