libata: limit post SRST nsect/lbal wait to ~100ms (e141d999) · Commits · 戴 / test

After SRST, libata used to wait for nsect/lbal to be set to 1/1 for the slave device. However, some ATAPI devices don't set nsect/lbal after SRST and the wait itself isn't too useful as we're gonna wait for !BSY right after that anyway. Before reset-seq update, nsect/lbal wait failure used to be ignored and caused 30sec delay during detection. After reset-seq, all timeouts are considered error conditions making libata fail to detect such ATAPI devices. This patch limits nsect/lbal wait to around 100ms. This should give acceptable behavior to such ATAPI devices while not disturbing the heavily used code path too much. Signed-off-by:

Tejun Heo <htejun@gmail.com> Signed-off-by:

Jeff Garzik <jeff@garzik.org>

drivers/ata/libata-core.c

+19 −13

Original line number	Diff line number	Diff line
		@@ -3061,22 +3061,28 @@ static int ata_bus_post_reset(struct ata_port *ap, unsigned int devmask,
		}
		}

		/* if device 1 was found in ata_devchk, wait for
		* register access, then wait for BSY to clear
		/* if device 1 was found in ata_devchk, wait for register
		* access briefly, then wait for BSY to clear.
		*/
		while (dev1) {
		u8 nsect, lbal;
		if (dev1) {
		int i;

		ap->ops->dev_select(ap, 1);

		/* Wait for register access. Some ATAPI devices fail
		* to set nsect/lbal after reset, so don't waste too
		* much time on it. We're gonna wait for !BSY anyway.
		*/
		for (i = 0; i < 2; i++) {
		u8 nsect, lbal;

		nsect = ioread8(ioaddr->nsect_addr);
		lbal = ioread8(ioaddr->lbal_addr);
		if ((nsect == 1) && (lbal == 1))
		break;
		if (time_after(jiffies, deadline))
		return -EBUSY;
		msleep(50); /* give drive a breather */
		}
		if (dev1) {

		rc = ata_wait_ready(ap, deadline);
		if (rc) {
		if (rc != -ENODEV)

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