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| author | Albert Lee <albertcc@tw.ibm.com> | 2006-05-18 17:51:10 +0800 |
|---|---|---|
| committer | Jeff Garzik <jeff@garzik.org> | 2006-05-20 00:37:01 -0400 |
| commit | eec4c3f317991dc85c786ffccd9c1a8620c41b18 (patch) | |
| tree | 0ba309ca3e7df22295c43181715f7b0c445a92b1 /drivers | |
| parent | 3655d1d323386e001c786af10f0a3f39f438f03b (diff) | |
| download | linux-3.10-eec4c3f317991dc85c786ffccd9c1a8620c41b18.tar.gz linux-3.10-eec4c3f317991dc85c786ffccd9c1a8620c41b18.tar.bz2 linux-3.10-eec4c3f317991dc85c786ffccd9c1a8620c41b18.zip | |
[PATCH] libata: use qc->result_tf for temp taskfile storage
Use qc->result_tf for temp taskfile storage.
Signed-off-by: Albert Lee <albertcc@tw.ibm.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/scsi/libata-core.c | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/drivers/scsi/libata-core.c b/drivers/scsi/libata-core.c index aa38ed3e59a..bf00d2b2e40 100644 --- a/drivers/scsi/libata-core.c +++ b/drivers/scsi/libata-core.c @@ -3865,10 +3865,16 @@ static void atapi_pio_bytes(struct ata_queued_cmd *qc) unsigned int ireason, bc_lo, bc_hi, bytes; int i_write, do_write = (qc->tf.flags & ATA_TFLAG_WRITE) ? 1 : 0; - ap->ops->tf_read(ap, &qc->tf); - ireason = qc->tf.nsect; - bc_lo = qc->tf.lbam; - bc_hi = qc->tf.lbah; + /* Abuse qc->result_tf for temp storage of intermediate TF + * here to save some kernel stack usage. + * For normal completion, qc->result_tf is not relevant. For + * error, qc->result_tf is later overwritten by ata_qc_complete(). + * So, the correctness of qc->result_tf is not affected. + */ + ap->ops->tf_read(ap, &qc->result_tf); + ireason = qc->result_tf.nsect; + bc_lo = qc->result_tf.lbam; + bc_hi = qc->result_tf.lbah; bytes = (bc_hi << 8) | bc_lo; /* shall be cleared to zero, indicating xfer of data */ |