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authorPaul Mundt <lethal@linux-sh.org>2007-11-08 11:14:56 +0900
committerJeff Garzik <jeff@garzik.org>2007-11-08 13:08:41 -0500
commit3d46b2e2faa56d12c6d51bf1071fd11abd009d0b (patch)
treebe1b269c820068407c7f289c64948b8f8a63b8b8
parent6004bda1cce51273ac9e71a39e680831b9ff4503 (diff)
libata: Support PIO polling-only hosts.
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>
-rw-r--r--drivers/ata/libata-core.c10
1 files changed, 10 insertions, 0 deletions
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index ec3ce120a51..89fd0e9ed74 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -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)