From: Alan Cox 2.6.21-rc has horrible problems with libata and PATA cable types (and thus speeds). This occurs because Tejun fixed a pile of other bugs and we now do cable detect enforcement for drive side detection properly. Unfortunately we don't do the process around cable detection right. Tejun identified the problem and pointed to the right Annex in the spec, this patch implements the needed changes. The basic requirement is that we have to identify the slave before the master. The patch switches the identify order so that we can do the drive side detection correctly. Secondly we add a ->cable_detect() method called after the identify sequence which allows a host to do host side detection at this point should it wish, or to modify the results of the drive side identify. This separate ->cable_detect method also cleans up a lot of code because many drivers have their own error_handler methods which really just set the cable type. If there is no ->cable_detect method the cable type is left alone so a driver setting it earlier (eg because it has the SATA flags set or because it uses the old error_handler approach) will still do the right thing (or at least the same thing) as before. This patch simply adds the cable_detect method and helpers it doesn't use them but other follow up patches will (ie Adrian please don't submit patches to unexport them ;)) Signed-off-by: Alan Cox Signed-off-by: Andrew Morton --- drivers/ata/libata-core.c | 75 +++++++++++++++++++++++++++++++++++- include/linux/libata.h | 7 +++ 2 files changed, 80 insertions(+), 2 deletions(-) diff -puN drivers/ata/libata-core.c~libata-cable-detection-fixes drivers/ata/libata-core.c --- a/drivers/ata/libata-core.c~libata-cable-detection-fixes +++ a/drivers/ata/libata-core.c @@ -1800,6 +1800,56 @@ err_out_nosup: } /** + * ata_cable_40wire - return 40pin cable type + * @ap: port + * + * Helper method for drivers which want to hardwire 40 pin cable + * detection. + */ + +int ata_cable_40wire(struct ata_port *ap) +{ + return ATA_CBL_PATA40; +} + +/** + * ata_cable_80wire - return 40pin cable type + * @ap: port + * + * Helper method for drivers which want to hardwire 80 pin cable + * detection. + */ + +int ata_cable_80wire(struct ata_port *ap) +{ + return ATA_CBL_PATA80; +} + +/** + * ata_cable_unknown - return unknown PATA cable. + * @ap: port + * + * Helper method for drivers which have no PATA cable detection. + */ + +int ata_cable_unknown(struct ata_port *ap) +{ + return ATA_CBL_PATA_UNK; +} + +/** + * ata_cable_sata - return SATA cable type + * @ap: port + * + * Helper method for drivers which have SATA cables + */ + +int ata_cable_sata(struct ata_port *ap) +{ + return ATA_CBL_SATA; +} + +/** * ata_bus_probe - Reset and probe ATA bus * @ap: Bus to probe * @@ -1850,8 +1900,11 @@ int ata_bus_probe(struct ata_port *ap) for (i = 0; i < ATA_MAX_DEVICES; i++) ap->device[i].pio_mode = XFER_PIO_0; - /* read IDENTIFY page and configure devices */ - for (i = 0; i < ATA_MAX_DEVICES; i++) { + /* read IDENTIFY page and configure devices. We have to do the identify + specific sequence bass-ackwards so that PDIAG- is released by + the slave device */ + + for (i = ATA_MAX_DEVICES - 1; i >= 0; i--) { dev = &ap->device[i]; if (tries[i]) @@ -1864,6 +1917,19 @@ int ata_bus_probe(struct ata_port *ap) dev->id); if (rc) goto fail; + } + + /* Now ask for the cable type as PDIAG- should have been released */ + if (ap->ops->cable_detect) + ap->cbl = ap->ops->cable_detect(ap); + + /* After the identify sequence we can now set up the devices. We do + this in the normal order so that the user doesn't get confused */ + + for(i = 0; i < ATA_MAX_DEVICES; i++) { + dev = &ap->device[i]; + if (!ata_dev_enabled(dev)) + continue; ap->eh_context.i.flags |= ATA_EHI_PRINTINFO; rc = ata_dev_configure(dev); @@ -6432,3 +6498,8 @@ EXPORT_SYMBOL_GPL(ata_dummy_irq_on); EXPORT_SYMBOL_GPL(ata_irq_ack); EXPORT_SYMBOL_GPL(ata_dummy_irq_ack); EXPORT_SYMBOL_GPL(ata_dev_try_classify); + +EXPORT_SYMBOL_GPL(ata_cable_40wire); +EXPORT_SYMBOL_GPL(ata_cable_80wire); +EXPORT_SYMBOL_GPL(ata_cable_unknown); +EXPORT_SYMBOL_GPL(ata_cable_sata); diff -puN include/linux/libata.h~libata-cable-detection-fixes include/linux/libata.h --- a/include/linux/libata.h~libata-cable-detection-fixes +++ a/include/linux/libata.h @@ -615,6 +615,8 @@ struct ata_port_operations { void (*post_set_mode) (struct ata_port *ap); + int (*cable_detect) (struct ata_port *ap); + int (*check_atapi_dma) (struct ata_queued_cmd *qc); void (*bmdma_setup) (struct ata_queued_cmd *qc); @@ -830,6 +832,11 @@ extern u8 ata_dummy_irq_on(struct ata_po extern u8 ata_irq_ack(struct ata_port *ap, unsigned int chk_drq); extern u8 ata_dummy_irq_ack(struct ata_port *ap, unsigned int chk_drq); +extern int ata_cable_40wire(struct ata_port *ap); +extern int ata_cable_80wire(struct ata_port *ap); +extern int ata_cable_sata(struct ata_port *ap); +extern int ata_cable_unknown(struct ata_port *ap); + /* * Timing helpers */ _