</authorgroup>
<copyright>
- <year>2003-2005</year>
+ <year>2003-2006</year>
<holder>Jeff Garzik</holder>
</copyright>
<programlisting>
void (*set_piomode) (struct ata_port *, struct ata_device *);
void (*set_dmamode) (struct ata_port *, struct ata_device *);
-void (*post_set_mode) (struct ata_port *ap);
+void (*post_set_mode) (struct ata_port *);
+unsigned int (*mode_filter) (struct ata_port *, struct ata_device *, unsigned int);
</programlisting>
<para>
Hooks called prior to the issue of SET FEATURES - XFER MODE
- command. dev->pio_mode is guaranteed to be valid when
- ->set_piomode() is called, and dev->dma_mode is guaranteed to be
- valid when ->set_dmamode() is called. ->post_set_mode() is
+ command. The optional ->mode_filter() hook is called when libata
+ has built a mask of the possible modes. This is passed to the
+ ->mode_filter() function which should return a mask of valid modes
+ after filtering those unsuitable due to hardware limits. It is not
+ valid to use this interface to add modes.
+ </para>
+ <para>
+ dev->pio_mode and dev->dma_mode are guaranteed to be valid when
+ ->set_piomode() and when ->set_dmamode() is called. The timings for
+ any other drive sharing the cable will also be valid at this point.
+ That is the library records the decisions for the modes of each
+ drive on a channel before it attempts to set any of them.
+ </para>
+ <para>
+ ->post_set_mode() is
called unconditionally, after the SET FEATURES - XFER MODE
command completes successfully.
</para>
</sect2>
+ <sect2><title>PIO data read/write</title>
+ <programlisting>
+void (*data_xfer) (struct ata_device *, unsigned char *, unsigned int, int);
+ </programlisting>
+
+ <para>
+All bmdma-style drivers must implement this hook. This is the low-level
+operation that actually copies the data bytes during a PIO data
+transfer.
+Typically the driver
+will choose one of ata_pio_data_xfer_noirq(), ata_pio_data_xfer(), or
+ata_mmio_data_xfer().
+ </para>
+
+ </sect2>
+
<sect2><title>ATA command execute</title>
<programlisting>
void (*exec_command)(struct ata_port *ap, struct ata_taskfile *tf);
<programlisting>
u8 (*check_status)(struct ata_port *ap);
u8 (*check_altstatus)(struct ata_port *ap);
-u8 (*check_err)(struct ata_port *ap);
</programlisting>
<para>
- Reads the Status/AltStatus/Error ATA shadow register from
+ Reads the Status/AltStatus ATA shadow register from
hardware. On some hardware, reading the Status register has
the side effect of clearing the interrupt condition.
Most drivers for taskfile-based hardware use
</sect2>
- <sect2><title>Reset ATA bus</title>
+ <sect2><title>Private tuning method</title>
<programlisting>
-void (*phy_reset) (struct ata_port *ap);
+void (*set_mode) (struct ata_port *ap);
</programlisting>
<para>
- The very first step in the probe phase. Actions vary depending
- on the bus type, typically. After waking up the device and probing
- for device presence (PATA and SATA), typically a soft reset
- (SRST) will be performed. Drivers typically use the helper
- functions ata_bus_reset() or sata_phy_reset() for this hook.
- Many SATA drivers use sata_phy_reset() or call it from within
- their own phy_reset() functions.
+ By default libata performs drive and controller tuning in
+ accordance with the ATA timing rules and also applies blacklists
+ and cable limits. Some controllers need special handling and have
+ custom tuning rules, typically raid controllers that use ATA
+ commands but do not actually do drive timing.
</para>
+ <warning>
+ <para>
+ This hook should not be used to replace the standard controller
+ tuning logic when a controller has quirks. Replacing the default
+ tuning logic in that case would bypass handling for drive and
+ bridge quirks that may be important to data reliability. If a
+ controller needs to filter the mode selection it should use the
+ mode_filter hook instead.
+ </para>
+ </warning>
+
</sect2>
<sect2><title>Control PCI IDE BMDMA engine</title>
</sect2>
- <sect2><title>Timeout (error) handling</title>
+ <sect2><title>Exception and probe handling (EH)</title>
<programlisting>
void (*eng_timeout) (struct ata_port *ap);
+void (*phy_reset) (struct ata_port *ap);
+ </programlisting>
+
+ <para>
+Deprecated. Use ->error_handler() instead.
+ </para>
+
+ <programlisting>
+void (*freeze) (struct ata_port *ap);
+void (*thaw) (struct ata_port *ap);
+ </programlisting>
+
+ <para>
+ata_port_freeze() is called when HSM violations or some other
+condition disrupts normal operation of the port. A frozen port
+is not allowed to perform any operation until the port is
+thawed, which usually follows a successful reset.
+ </para>
+
+ <para>
+The optional ->freeze() callback can be used for freezing the port
+hardware-wise (e.g. mask interrupt and stop DMA engine). If a
+port cannot be frozen hardware-wise, the interrupt handler
+must ack and clear interrupts unconditionally while the port
+is frozen.
+ </para>
+ <para>
+The optional ->thaw() callback is called to perform the opposite of ->freeze():
+prepare the port for normal operation once again. Unmask interrupts,
+start DMA engine, etc.
+ </para>
+
+ <programlisting>
+void (*error_handler) (struct ata_port *ap);
+ </programlisting>
+
+ <para>
+->error_handler() is a driver's hook into probe, hotplug, and recovery
+and other exceptional conditions. The primary responsibility of an
+implementation is to call ata_do_eh() or ata_bmdma_drive_eh() with a set
+of EH hooks as arguments:
+ </para>
+
+ <para>
+'prereset' hook (may be NULL) is called during an EH reset, before any other actions
+are taken.
+ </para>
+
+ <para>
+'postreset' hook (may be NULL) is called after the EH reset is performed. Based on
+existing conditions, severity of the problem, and hardware capabilities,
+ </para>
+
+ <para>
+Either 'softreset' (may be NULL) or 'hardreset' (may be NULL) will be
+called to perform the low-level EH reset.
+ </para>
+
+ <programlisting>
+void (*post_internal_cmd) (struct ata_queued_cmd *qc);
</programlisting>
<para>
-This is a high level error handling function, called from the
-error handling thread, when a command times out. Most newer
-hardware will implement its own error handling code here. IDE BMDMA
-drivers may use the helper function ata_eng_timeout().
+Perform any hardware-specific actions necessary to finish processing
+after executing a probe-time or EH-time command via ata_exec_internal().
</para>
</sect2>
<sect1><title>ata_scsi_error()</title>
<para>
- ata_scsi_error() is the current hostt->eh_strategy_handler()
+ ata_scsi_error() is the current transportt->eh_strategy_handler()
for libata. As discussed above, this will be entered in two
cases - timeout and ATAPI error completion. This function
calls low level libata driver's eng_timeout() callback, the
<chapter id="libataExt">
<title>libata Library</title>
-!Edrivers/scsi/libata-core.c
+!Edrivers/ata/libata-core.c
</chapter>
<chapter id="libataInt">
<title>libata Core Internals</title>
-!Idrivers/scsi/libata-core.c
+!Idrivers/ata/libata-core.c
</chapter>
<chapter id="libataScsiInt">
<title>libata SCSI translation/emulation</title>
-!Edrivers/scsi/libata-scsi.c
-!Idrivers/scsi/libata-scsi.c
+!Edrivers/ata/libata-scsi.c
+!Idrivers/ata/libata-scsi.c
</chapter>
<chapter id="ataExceptions">
- <title>ATA errors & exceptions</title>
+ <title>ATA errors and exceptions</title>
<para>
This chapter tries to identify what error/exception conditions exist
<listitem>
<para>
When it's known that HBA is in ready state but ATA/ATAPI
- device in in unknown state, reset only device.
+ device is in unknown state, reset only device.
</para>
</listitem>
<chapter id="PiixInt">
<title>ata_piix Internals</title>
-!Idrivers/scsi/ata_piix.c
+!Idrivers/ata/ata_piix.c
</chapter>
<chapter id="SILInt">
<title>sata_sil Internals</title>
-!Idrivers/scsi/sata_sil.c
+!Idrivers/ata/sata_sil.c
</chapter>
<chapter id="libataThanks">
git://git.onelab.eu / linux-2.6.git / blobdiff