diff options
Diffstat (limited to 'Documentation/DocBook')
| -rw-r--r-- | Documentation/DocBook/libata.tmpl | 58 |
1 files changed, 39 insertions, 19 deletions
diff --git a/Documentation/DocBook/libata.tmpl b/Documentation/DocBook/libata.tmpl index 773ae9fd99d..41053aed41f 100644 --- a/Documentation/DocBook/libata.tmpl +++ b/Documentation/DocBook/libata.tmpl @@ -14,7 +14,7 @@ </authorgroup> <copyright> - <year>2003</year> + <year>2003-2005</year> <holder>Jeff Garzik</holder> </copyright> @@ -145,14 +145,25 @@ void (*exec_command)(struct ata_port *ap, struct ata_taskfile *tf); </para> <programlisting> +int (*check_atapi_dma) (struct ata_queued_cmd *qc); + </programlisting> + + <para> +Allow low-level driver to filter ATA PACKET commands, returning a status +indicating whether or not it is OK to use DMA for the supplied PACKET +command. + </para> + + <programlisting> u8 (*check_status)(struct ata_port *ap); -void (*dev_select)(struct ata_port *ap, unsigned int device); +u8 (*check_altstatus)(struct ata_port *ap); +u8 (*check_err)(struct ata_port *ap); </programlisting> <para> - Reads the Status ATA shadow register from hardware. On some - hardware, this has the side effect of clearing the interrupt - condition. + Reads the Status/AltStatus/Error ATA shadow register from + hardware. On some hardware, reading the Status register has + the side effect of clearing the interrupt condition. </para> <programlisting> @@ -162,7 +173,8 @@ void (*dev_select)(struct ata_port *ap, unsigned int device); <para> Issues the low-level hardware command(s) that causes one of N hardware devices to be considered 'selected' (active and - available for use) on the ATA bus. + available for use) on the ATA bus. This generally has no +meaning on FIS-based devices. </para> <programlisting> @@ -180,12 +192,20 @@ void (*phy_reset) (struct ata_port *ap); <programlisting> void (*bmdma_setup) (struct ata_queued_cmd *qc); void (*bmdma_start) (struct ata_queued_cmd *qc); +void (*bmdma_stop) (struct ata_port *ap); +u8 (*bmdma_status) (struct ata_port *ap); </programlisting> <para> - When setting up an IDE BMDMA transaction, these hooks arm - (->bmdma_setup) and fire (->bmdma_start) the hardware's DMA - engine. +When setting up an IDE BMDMA transaction, these hooks arm +(->bmdma_setup), fire (->bmdma_start), and halt (->bmdma_stop) +the hardware's DMA engine. ->bmdma_status is used to read the standard +PCI IDE DMA Status register. + </para> + + <para> +These hooks are typically either no-ops, or simply not implemented, in +FIS-based drivers. </para> <programlisting> @@ -205,9 +225,7 @@ int (*qc_issue) (struct ata_queued_cmd *qc); ->qc_issue is used to make a command active, once the hardware and S/G tables have been prepared. IDE BMDMA drivers use the helper function ata_qc_issue_prot() for taskfile protocol-based - dispatch. More advanced drivers roll their own ->qc_issue - implementation, using this as the "issue new ATA command to - hardware" hook. + dispatch. More advanced drivers implement their own ->qc_issue. </para> <programlisting> @@ -215,8 +233,10 @@ void (*eng_timeout) (struct ata_port *ap); </programlisting> <para> - This is a high level error handling function, called from the - error handling thread, when a command times out. +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(). </para> <programlisting> @@ -255,15 +275,15 @@ void (*host_stop) (struct ata_host_set *host_set); tasks. </para> <para> - ->host_stop() is called when the rmmod or hot unplug process - begins. The hook must stop all hardware interrupts, DMA - engines, etc. - </para> - <para> ->port_stop() is called after ->host_stop(). It's sole function is to release DMA/memory resources, now that they are no longer actively being used. </para> + <para> + ->host_stop() is called after all ->port_stop() calls +have completed. The hook must finalize hardware shutdown, release DMA +and other resources, etc. + </para> </sect1> </chapter> |