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| author | Tejun Heo <htejun@gmail.com> | 2006-07-26 08:59:26 +0200 |
|---|---|---|
| committer | Jeff Garzik <jeff@garzik.org> | 2006-07-29 10:01:31 +0200 |
| commit | 9f5920567bfabbd1be26112a31c44652b6587394 (patch) | |
| tree | 27e06539d48f05b85693ba2e9854ebf9a5a4abd7 /drivers/scsi/ahci.c | |
| parent | [PATCH] ahci: cosmetic changes to ahci_start/stop_engine() (diff) | |
| download | linux-9f5920567bfabbd1be26112a31c44652b6587394.tar.xz linux-9f5920567bfabbd1be26112a31c44652b6587394.zip | |
[PATCH] ahci: simplify ahci_start_engine()
Simplify ahci_start_engine() by killing prerequisite condition checks.
Rationales are..
* No user checks error return from ahci_start_engine()
* Code flow guarantees the prerequisite conditions unless the
controller is malfunctioning. In such cases, the driver had chances
to learn about the problem _before_ calling this function.
* Closely related to the above two, driver calls into this function
even when prerequisites fail hoping for the best.
Basically, ahci_start_engine() should only do the operation itself.
It isn't the right place to check for prerequisites.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Zhao, Forrest <forrest.zhao@intel.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Diffstat (limited to 'drivers/scsi/ahci.c')
| -rw-r--r-- | drivers/scsi/ahci.c | 21 |
1 files changed, 2 insertions, 19 deletions
diff --git a/drivers/scsi/ahci.c b/drivers/scsi/ahci.c index ee00aed9bdea..e02b9c65287b 100644 --- a/drivers/scsi/ahci.c +++ b/drivers/scsi/ahci.c @@ -406,32 +406,15 @@ static void ahci_scr_write (struct ata_port *ap, unsigned int sc_reg_in, writel(val, (void __iomem *) ap->ioaddr.scr_addr + (sc_reg * 4)); } -static int ahci_start_engine(void __iomem *port_mmio) +static void ahci_start_engine(void __iomem *port_mmio) { u32 tmp; - /* get current status */ - tmp = readl(port_mmio + PORT_CMD); - - /* AHCI rev 1.1 section 10.3.1: - * Software shall not set PxCMD.ST to '1' until it verifies - * that PxCMD.CR is '0' and has set PxCMD.FRE to '1' - */ - if ((tmp & PORT_CMD_FIS_RX) == 0) - return -EPERM; - - /* wait for engine to become idle */ - tmp = ata_wait_register(port_mmio + PORT_CMD, - PORT_CMD_LIST_ON, PORT_CMD_LIST_ON, 1,500); - if (tmp & PORT_CMD_LIST_ON) - return -EBUSY; - /* start DMA */ + tmp = readl(port_mmio + PORT_CMD); tmp |= PORT_CMD_START; writel(tmp, port_mmio + PORT_CMD); readl(port_mmio + PORT_CMD); /* flush */ - - return 0; } static int ahci_stop_engine(void __iomem *port_mmio) |