[libata] change master/slave IDENTIFY order (f31f0cc2) · Commits · 戴 / test

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. [NOTE: patch and description extracted from a larger work written and signed-off-by Alan Cox] Signed-off-by:

Jeff Garzik <jeff@garzik.org>

drivers/ata/libata-core.c

+14 −2

Original line number	Diff line number	Diff line
		@@ -1850,8 +1850,11 @@ 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 +1867,15 @@ int ata_bus_probe(struct ata_port *ap)
		dev->id);
		if (rc)
		goto fail;
		}

		/* 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);

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