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Commit 24920c8a authored by Zhang Rui's avatar Zhang Rui Committed by Jeff Garzik
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AHCI: speed up resume 



During resume, sleep 1 second to wait for the HBA reset
to finish is a waste of time.

According to the AHCI 1.2 spec,
We should poll the HOST_CTL register,
and return error if the host reset is not
finished within 1 second.

Test results show that the HBA reset can be done quickly(in usecs).
And this patch may save nearly 1 second during resume.

Signed-off-by: default avatarZhang Rui <rui.zhang@intel.com>
Signed-off-by: default avatarJeff Garzik <jgarzik@redhat.com>
parent 1e9dbc92

drivers/ata/ahci.c

+6 −3
Original line number Original line Diff line number Diff line
@@ -1142,12 +1142,15 @@ static int ahci_reset_controller(struct ata_host *host) 
			readl(mmio + HOST_CTL); /* flush */

			readl(mmio + HOST_CTL); /* flush */

		}

		}





		/* reset must complete within 1 second, or

		/*

		 * to perform host reset, OS should set HOST_RESET

		 * and poll until this bit is read to be "0".

		 * reset must complete within 1 second, or

		 * the hardware should be considered fried.

		 * the hardware should be considered fried.

		 */

		 */

		ssleep(1);

		tmp = ata_wait_register(mmio + HOST_CTL, HOST_RESET,

					HOST_RESET, 10, 1000);





		tmp = readl(mmio + HOST_CTL);

		if (tmp & HOST_RESET) {

		if (tmp & HOST_RESET) {

			dev_printk(KERN_ERR, host->dev,

			dev_printk(KERN_ERR, host->dev,

				   "controller reset failed (0x%x)\n", tmp);

				   "controller reset failed (0x%x)\n", tmp);