libata: Fixup n_elem initialization (7a801184) · Commits · 戴 / test

Fixup the inialization of qc->n_elem. It currently gets initialized to 1 for commands that do not transfer any data. Fix this by initializing n_elem to 0 and only setting to 1 in ata_scsi_qc_new when there is data to transfer. This fixes some problems seen with SATA devices attached to ipr adapters. Signed-off-by:

Brian King <brking@linux.vnet.ibm.com> Signed-off-by:

Jeff Garzik <jeff@garzik.org>

drivers/ata/libata-scsi.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -372,7 +372,7 @@ struct ata_queued_cmd ata_scsi_qc_new(struct ata_device dev,
		if (cmd->use_sg) {
		qc->__sg = (struct scatterlist *) cmd->request_buffer;
		qc->n_elem = cmd->use_sg;
		} else {
		} else if (cmd->request_bufflen) {
		qc->__sg = &qc->sgent;
		qc->n_elem = 1;
		}

include/linux/libata.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -1149,6 +1149,7 @@ static inline void ata_qc_reinit(struct ata_queued_cmd *qc)
		qc->cursect = qc->cursg = qc->cursg_ofs = 0;
		qc->nsect = 0;
		qc->nbytes = qc->curbytes = 0;
		qc->n_elem = 0;
		qc->err_mask = 0;

		ata_tf_init(qc->dev, &qc->tf);

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