From: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Date: Sat, 18 Aug 2007 09:27:36 +0000 (+0900)
Subject: libata sg chaining support fix
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=0874ee76bcd06e2f53c32a56773ad82f5920f0f9;p=GitHub%2Fmt8127%2Fandroid_kernel_alcatel_ttab.git

libata sg chaining support fix

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
---

diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index e52c33180e42..bbaa545ea999 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -4952,16 +4952,18 @@ static void __atapi_pio_bytes(struct ata_queued_cmd *qc, unsigned int bytes)
 {
 	int do_write = (qc->tf.flags & ATA_TFLAG_WRITE);
 	struct scatterlist *sg = qc->__sg;
+	struct scatterlist *lsg = sg_last(qc->__sg, qc->n_elem);
 	struct ata_port *ap = qc->ap;
 	struct page *page;
 	unsigned char *buf;
 	unsigned int offset, count;
+	int no_more_sg = 0;
 
 	if (qc->curbytes + bytes >= qc->nbytes)
 		ap->hsm_task_state = HSM_ST_LAST;
 
 next_sg:
-	if (unlikely(qc->cursg == sg_last(qc->__sg, qc->n_elem))) {
+	if (unlikely(no_more_sg)) {
 		/*
 		 * The end of qc->sg is reached and the device expects
 		 * more data to transfer. In order not to overrun qc->sg
@@ -5023,6 +5025,9 @@ next_sg:
 	qc->cursg_ofs += count;
 
 	if (qc->cursg_ofs == sg->length) {
+		if (qc->cursg == lsg)
+			no_more_sg = 1;
+
 		qc->cursg = sg_next(qc->cursg);
 		qc->cursg_ofs = 0;
 	}