From 9f5920567bfabbd1be26112a31c44652b6587394 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Wed, 26 Jul 2006 15:59:26 +0900 Subject: [PATCH] [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 Signed-off-by: Zhao, Forrest Signed-off-by: Jeff Garzik --- drivers/scsi/ahci.c | 21 ++------------------- 1 file changed, 2 insertions(+), 19 deletions(-) diff --git a/drivers/scsi/ahci.c b/drivers/scsi/ahci.c index ee00aed9bd..e02b9c6528 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) -- 2.39.2