From 1ffc151fcddf524d0c76709d7e7a2af0255acb6b Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Sun, 23 Mar 2008 15:16:53 +0900 Subject: [PATCH] libata: assume no device is attached if both IDENTIFYs are aborted MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit This is to fix bugzilla #10254. QSI cdrom attached to pata_sis as secondary master appears as phantom device for the slave. Interestingly, instead of not setting DRQ after IDENTIFY which triggers NODEV_HINT, it aborts both IDENTIFY and IDENTIFY PACKET which makes EH retry. Modify EH such that it assumes no device is attached if both flavors of IDENTIFY are aborted by the device. There really isn't much point in retrying when the device actively aborts the commands. While at it, convert NODEV detection message to ata_dev_printk() to help debugging obscure detection problems. This problem was reported by Jan Bücken. Signed-off-by: Tejun Heo Cc: Jan Bücken Acked-by: Alan Cox Signed-off-by: Jeff Garzik --- drivers/ata/libata-core.c | 38 ++++++++++++++++++++++++-------------- 1 file changed, 24 insertions(+), 14 deletions(-) diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c index 4bbe31f98ef..c9c52803d0c 100644 --- a/drivers/ata/libata-core.c +++ b/drivers/ata/libata-core.c @@ -2092,24 +2092,34 @@ int ata_dev_read_id(struct ata_device *dev, unsigned int *p_class, id, sizeof(id[0]) * ATA_ID_WORDS, 0); if (err_mask) { if (err_mask & AC_ERR_NODEV_HINT) { - DPRINTK("ata%u.%d: NODEV after polling detection\n", - ap->print_id, dev->devno); + ata_dev_printk(dev, KERN_DEBUG, + "NODEV after polling detection\n"); return -ENOENT; } - /* Device or controller might have reported the wrong - * device class. Give a shot at the other IDENTIFY if - * the current one is aborted by the device. - */ - if (may_fallback && - (err_mask == AC_ERR_DEV) && (tf.feature & ATA_ABORTED)) { - may_fallback = 0; + if ((err_mask == AC_ERR_DEV) && (tf.feature & ATA_ABORTED)) { + /* Device or controller might have reported + * the wrong device class. Give a shot at the + * other IDENTIFY if the current one is + * aborted by the device. + */ + if (may_fallback) { + may_fallback = 0; - if (class == ATA_DEV_ATA) - class = ATA_DEV_ATAPI; - else - class = ATA_DEV_ATA; - goto retry; + if (class == ATA_DEV_ATA) + class = ATA_DEV_ATAPI; + else + class = ATA_DEV_ATA; + goto retry; + } + + /* Control reaches here iff the device aborted + * both flavors of IDENTIFYs which happens + * sometimes with phantom devices. + */ + ata_dev_printk(dev, KERN_DEBUG, + "both IDENTIFYs aborted, assuming NODEV\n"); + return -ENOENT; } rc = -EIO; -- 2.41.0