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-rw-r--r--Documentation/DocBook/libata.tmpl47
1 files changed, 43 insertions, 4 deletions
diff --git a/Documentation/DocBook/libata.tmpl b/Documentation/DocBook/libata.tmpl
index d260d92089ad..5bcbb6ee3bc0 100644
--- a/Documentation/DocBook/libata.tmpl
+++ b/Documentation/DocBook/libata.tmpl
@@ -120,14 +120,27 @@ void (*dev_config) (struct ata_port *, struct ata_device *);
<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>
@@ -230,6 +243,32 @@ void (*dev_select)(struct ata_port *ap, unsigned int device);
</sect2>
+ <sect2><title>Private tuning method</title>
+ <programlisting>
+void (*set_mode) (struct ata_port *ap);
+ </programlisting>
+
+ <para>
+ 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>Reset ATA bus</title>
<programlisting>
void (*phy_reset) (struct ata_port *ap);