The patch titled
sata_nv: don't read shadow registers when in ADMA mode
has been added to the -mm tree. Its filename is
sata_nv-dont-read-shadow-registers-when-in-adma-mode.patch
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: sata_nv: don't read shadow registers when in ADMA mode
From: Robert Hancock <[EMAIL PROTECTED]>
Reading from the ATA shadow registers while we are in ADMA mode may cause
undefined behavior. Don't read the ATA status register when completing
commands for this reason, it shouldn't be needed as the controller will
notify us if the command failed. Also, don't allow commands with result
taskfile requested to execute in ADMA mode, since that requires accessing
the shadow registers. We also still need to override tf_read since libata
will read the result taskfile on a command failure, and we need to go into
port register mode before allowing this.
Signed-off-by: Robert Hancock <[EMAIL PROTECTED]>
Signed-off-by: Andrew Morton <[EMAIL PROTECTED]>
---
drivers/ata/sata_nv.c | 33 ++++++++++++++++++++-------------
1 file changed, 20 insertions(+), 13 deletions(-)
diff -puN
drivers/ata/sata_nv.c~sata_nv-dont-read-shadow-registers-when-in-adma-mode
drivers/ata/sata_nv.c
--- a/drivers/ata/sata_nv.c~sata_nv-dont-read-shadow-registers-when-in-adma-mode
+++ a/drivers/ata/sata_nv.c
@@ -260,6 +260,7 @@ static int nv_adma_port_resume(struct at
static void nv_adma_error_handler(struct ata_port *ap);
static void nv_adma_host_stop(struct ata_host *host);
static void nv_adma_post_internal_cmd(struct ata_queued_cmd *qc);
+static void nv_adma_tf_read(struct ata_port *ap, struct ata_taskfile *tf);
enum nv_host_type
{
@@ -435,7 +436,7 @@ static const struct ata_port_operations
static const struct ata_port_operations nv_adma_ops = {
.port_disable = ata_port_disable,
.tf_load = ata_tf_load,
- .tf_read = ata_tf_read,
+ .tf_read = nv_adma_tf_read,
.check_atapi_dma = nv_adma_check_atapi_dma,
.exec_command = ata_exec_command,
.check_status = ata_check_status,
@@ -667,6 +668,18 @@ static int nv_adma_check_atapi_dma(struc
return !(pp->flags & NV_ADMA_ATAPI_SETUP_COMPLETE);
}
+static void nv_adma_tf_read(struct ata_port *ap, struct ata_taskfile *tf)
+{
+ /* Since commands where a result TF is requested are not
+ executed in ADMA mode, the only time this function will be called
+ in ADMA mode will be if a command fails. In this case we
+ don't care about going into register mode with ADMA commands
+ pending, as the commands will all shortly be aborted anyway. */
+ nv_adma_register_mode(ap);
+
+ ata_tf_read(ap, tf);
+}
+
static unsigned int nv_adma_tf_to_cpb(struct ata_taskfile *tf, __le16 *cpb)
{
unsigned int idx = 0;
@@ -738,19 +751,11 @@ static int nv_adma_check_cpb(struct ata_
return 1;
}
- if (flags & NV_CPB_RESP_DONE) {
+ if (likely(flags & NV_CPB_RESP_DONE)) {
struct ata_queued_cmd *qc = ata_qc_from_tag(ap, cpb_num);
VPRINTK("CPB flags done, flags=0x%x\n", flags);
if (likely(qc)) {
- /* Grab the ATA port status for non-NCQ commands.
- For NCQ commands the current status may have nothing
to do with
- the command just completed. */
- if (qc->tf.protocol != ATA_PROT_NCQ) {
- u8 ata_status = readb(pp->ctl_block +
(ATA_REG_STATUS * 4));
- qc->err_mask |= ac_err_mask(ata_status);
- }
- DPRINTK("Completing qc from tag %d with err_mask
%u\n",cpb_num,
- qc->err_mask);
+ DPRINTK("Completing qc from tag %d\n",cpb_num);
ata_qc_complete(qc);
} else {
struct ata_eh_info *ehi = &ap->eh_info;
@@ -1161,9 +1166,11 @@ static int nv_adma_use_reg_mode(struct a
struct nv_adma_port_priv *pp = qc->ap->private_data;
/* ADMA engine can only be used for non-ATAPI DMA commands,
- or interrupt-driven no-data commands. */
+ or interrupt-driven no-data commands, where a result taskfile
+ is not required. */
if((pp->flags & NV_ADMA_ATAPI_SETUP_COMPLETE) ||
- (qc->tf.flags & ATA_TFLAG_POLLING))
+ (qc->tf.flags & ATA_TFLAG_POLLING) ||
+ (qc->flags & ATA_QCFLAG_RESULT_TF))
return 1;
if((qc->flags & ATA_QCFLAG_DMAMAP) ||
_
Patches currently in -mm which might be from [EMAIL PROTECTED] are
sata_nv-add-back-some-verbosity-into-adma-error_handler.patch
libata-warn-if-speed-limited-due-to-40-wire-cable-v2.patch
libata-add-ncq-blacklist-entries-from-silicon-image-windows.patch
sata_nv-dont-read-shadow-registers-when-in-adma-mode.patch
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