From e141d999b682cda9907179e3b843acb64c34a1d8 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Sun, 10 Jun 2007 14:26:20 +0900 Subject: [PATCH] libata: limit post SRST nsect/lbal wait to ~100ms 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 Signed-off-by: Jeff Garzik --- drivers/ata/libata-core.c | 32 +++++++++++++++++++------------- 1 file changed, 19 insertions(+), 13 deletions(-) diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c index 76aa94f..047eabd 100644 --- a/drivers/ata/libata-core.c +++ b/drivers/ata/libata-core.c @@ -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); - 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) { + + /* 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; + msleep(50); /* give drive a breather */ + } + rc = ata_wait_ready(ap, deadline); if (rc) { if (rc != -ENODEV) -- 1.8.2.3