libata: Support PIO polling-only hosts. (3d46b2e2) · Commits · 戴 / test

By default ata_host_activate() expects a valid IRQ in order to successfully register the host. This patch enables a special case for registering polling-only hosts that either don't have IRQs or have buggy IRQ generation (either in terms of handling or sensing), which otherwise work fine. Hosts that want to use polling mode can simply set ATA_FLAG_PIO_POLLING and pass in an invalid IRQ. Signed-off-by:

Paul Mundt <lethal@linux-sh.org> Signed-off-by:

Jeff Garzik <jeff@garzik.org>

drivers/ata/libata-core.c

+10 −0

Original line number	Diff line number	Diff line
		@@ -7178,6 +7178,10 @@ int ata_host_register(struct ata_host host, struct scsi_host_template sht)
		* request IRQ and register it. This helper takes necessasry
		* arguments and performs the three steps in one go.
		*
		* An invalid IRQ skips the IRQ registration and expects the host to
		* have set polling mode on the port. In this case, @irq_handler
		* should be NULL.
		*
		* LOCKING:
		* Inherited from calling layer (may sleep).
		*
		@@ -7194,6 +7198,12 @@ int ata_host_activate(struct ata_host *host, int irq,
		if (rc)
		return rc;

		/* Special case for polling mode */
		if (!irq) {
		WARN_ON(irq_handler);
		return ata_host_register(host, sht);
		}

		rc = devm_request_irq(host->dev, irq, irq_handler, irq_flags,
		dev_driver_string(host->dev), host);
		if (rc)

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