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Lines 561-587
void ahci_start_engine(struct ata_port *ap)
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| 561 |
{ |
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{ |
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void __iomem *port_mmio = ahci_port_base(ap); |
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void __iomem *port_mmio = ahci_port_base(ap); |
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u32 tmp; |
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u32 tmp; |
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u8 status; |
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status = readl(port_mmio + PORT_TFDATA) & 0xFF; |
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/* |
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* At end of section 10.1 of AHCI spec (rev 1.3), it states |
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* Software shall not set PxCMD.ST to 1 until it is determined |
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* that a functoinal device is present on the port as determined by |
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* PxTFD.STS.BSY=0, PxTFD.STS.DRQ=0 and PxSSTS.DET=3h |
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* |
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* Even though most AHCI host controllers work without this check, |
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* specific controller will fail under this condition |
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*/ |
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if (status & (ATA_BUSY | ATA_DRQ)) |
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return; |
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else { |
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ahci_scr_read(&ap->link, SCR_STATUS, &tmp); |
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if ((tmp & 0xf) != 0x3) |
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return; |
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} |
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/* start DMA */ |
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/* start DMA */ |
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tmp = readl(port_mmio + PORT_CMD); |
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tmp = readl(port_mmio + PORT_CMD); |
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