From: "Albert Lee" <albertcc@tw.ibm.com>
To: Jeff Garzik <jgarzik@pobox.com>
Cc: IDE Linux <linux-ide@vger.kernel.org>, Doug Maxey <dwm@maxeymade.com>
Subject: [PATCH 3/3] libata - Query the driver for ATAPI DMA support
Date: Wed, 15 Dec 2004 18:05:25 +0800 [thread overview]
Message-ID: <005201c4e28d$9a809280$f17a4109@tw.ibm.com> (raw)
[-- Attachment #1: Type: text/plain, Size: 5290 bytes --]
Hi, Jeff:
> After some testing, it seems that some PATA host adapter (ex. pdc20275) cannot
> work reliably with specific request buffer sizes under ATAPI DMA mode.
>
> Detailed test result:
> 4096, 2048, 1024, 512, 256: OK
> 384, 257, 255, 128, 96, 64, 32: failed (irq lost)
>
> It seems multiple of 256 bytes are the safe ATAPI DMA buffer sizes to use.
>
Attached please find the patch to fix the pdc2027x ATAPI DMA problem.
(The patch is against libata-dev-2.6 tree.)
Changes:
1. Add a callback function "check_atapi_dma()" to ata_port_operations such that libata core
can ask the driver: "Can this command be processed in ATAPI DMA mode safely? "
when the the command is received.
2. ATAPI DMA is off by default if the callback function is not provided by the driver
Albert
Signed-off-by: Albert Lee <albertcc@tw.ibm.com>
---
diff -Nru libata-dev-2.6-ori/drivers/scsi/libata-core.c libata-dev-2.6/drivers/scsi/libata-core.c
--- libata-dev-2.6-ori/drivers/scsi/libata-core.c 2004-12-15 16:10:30.000000000 +0800
+++ libata-dev-2.6/drivers/scsi/libata-core.c 2004-12-15 16:15:01.000000000 +0800
@@ -1947,7 +1947,24 @@
if (idx)
ap->prd[idx - 1].flags_len |= cpu_to_le32(ATA_PRD_EOT);
}
+/**
+ * ata_check_atapi_dma - Check whether ATAPI DMA can be supported
+ * @qc: Metadata associated with taskfile to check
+ *
+ * LOCKING:
+ * RETURNS: 0 when ATAPI DMA can be used
+ * nonzero otherwise
+ */
+int ata_check_atapi_dma(struct ata_queued_cmd *qc)
+{
+ struct ata_port *ap = qc->ap;
+ int rc = 1; /* Turn off ATAPI DMA by default */
+
+ if (ap->ops->check_atapi_dma)
+ rc = ap->ops->check_atapi_dma(qc);
+ return rc;
+}
/**
* ata_qc_prep - Prepare taskfile for submission
* @qc: Metadata associated with taskfile to be prepared
diff -Nru libata-dev-2.6-ori/drivers/scsi/libata.h libata-dev-2.6/drivers/scsi/libata.h
--- libata-dev-2.6-ori/drivers/scsi/libata.h 2004-11-30 12:52:28.000000000 +0800
+++ libata-dev-2.6/drivers/scsi/libata.h 2004-12-15 16:36:55.000000000 +0800
@@ -38,6 +38,7 @@
extern struct ata_queued_cmd *ata_qc_new_init(struct ata_port *ap,
struct ata_device *dev);
extern int ata_qc_issue(struct ata_queued_cmd *qc);
+extern int ata_check_atapi_dma(struct ata_queued_cmd *qc);
extern void ata_dev_select(struct ata_port *ap, unsigned int device,
unsigned int wait, unsigned int can_sleep);
extern void ata_tf_to_host_nolock(struct ata_port *ap, struct ata_taskfile *tf);
diff -Nru libata-dev-2.6-ori/drivers/scsi/libata-scsi.c libata-dev-2.6/drivers/scsi/libata-scsi.c
--- libata-dev-2.6-ori/drivers/scsi/libata-scsi.c 2004-11-30 12:52:28.000000000 +0800
+++ libata-dev-2.6/drivers/scsi/libata-scsi.c 2004-12-15 16:15:59.000000000 +0800
@@ -1558,6 +1558,11 @@
int using_pio = (dev->flags & ATA_DFLAG_PIO);
int nodata = (cmd->sc_data_direction == SCSI_DATA_NONE);
+ if (!using_pio)
+ /* Check whether ATAPI DMA is safe */
+ if (ata_check_atapi_dma(qc))
+ using_pio = 1;
+
memcpy(&qc->cdb, scsicmd, qc->ap->cdb_len);
qc->complete_fn = atapi_qc_complete;
diff -Nru libata-dev-2.6-ori/drivers/scsi/pata_pdc2027x.c libata-dev-2.6/drivers/scsi/pata_pdc2027x.c
--- libata-dev-2.6-ori/drivers/scsi/pata_pdc2027x.c 2004-11-30 12:52:28.000000000 +0800
+++ libata-dev-2.6/drivers/scsi/pata_pdc2027x.c 2004-12-15 16:21:00.000000000 +0800
@@ -29,7 +29,7 @@
#include <asm/io.h>
#define DRV_NAME "pata_pdc2027x"
-#define DRV_VERSION "0.53"
+#define DRV_VERSION "0.54"
#undef PDC_DEBUG
#ifdef PDC_DEBUG
@@ -51,6 +51,7 @@
static void pdc2027x_phy_reset(struct ata_port *ap);
static void pdc2027x_set_piomode(struct ata_port *ap, struct ata_device *adev);
static void pdc2027x_set_dmamode(struct ata_port *ap, struct ata_device *adev);
+static int pdc2027x_check_atapi_dma(struct ata_queued_cmd *qc);
/*
* ATA Timing Tables based on 133MHz controller clock.
@@ -141,6 +142,7 @@
.phy_reset = pdc2027x_phy_reset,
+ .check_atapi_dma = pdc2027x_check_atapi_dma,
.bmdma_setup = ata_bmdma_setup,
.bmdma_start = ata_bmdma_start,
.qc_prep = ata_qc_prep,
@@ -377,6 +379,27 @@
}
}
/**
+ * pdc2027x_check_atapi_dma - Check whether ATAPI DMA can be supported for this command
+ * @qc: Metadata associated with taskfile to check
+ *
+ * LOCKING:
+ * None (inherited from caller).
+ *
+ * RETURNS: 0 when ATAPI DMA can be used
+ * 1 otherwise
+ */
+static int pdc2027x_check_atapi_dma(struct ata_queued_cmd *qc)
+{
+ struct scsi_cmnd *cmd = qc->scsicmd;
+ int rc = 0;
+
+ /* pdc2027x can only do ATAPI DMA for specific buffer size */
+ if (cmd->request_bufflen % 256)
+ rc = 1;
+
+ return rc;
+}
+/**
* adjust_pll - Adjust the PLL input clock in Hz.
*
* @pdc_controller: controller specific information
diff -Nru libata-dev-2.6-ori/include/linux/libata.h libata-dev-2.6/include/linux/libata.h
--- libata-dev-2.6-ori/include/linux/libata.h 2004-11-30 12:52:42.000000000 +0800
+++ libata-dev-2.6/include/linux/libata.h 2004-12-15 16:17:41.000000000 +0800
@@ -339,6 +339,8 @@
void (*phy_reset) (struct ata_port *ap);
void (*post_set_mode) (struct ata_port *ap);
+ int (*check_atapi_dma) (struct ata_queued_cmd *qc);
+
void (*bmdma_setup) (struct ata_queued_cmd *qc);
void (*bmdma_start) (struct ata_queued_cmd *qc);
[-- Attachment #2: atapi_dma_check.patch --]
[-- Type: application/octet-stream, Size: 4572 bytes --]
diff -Nru libata-dev-2.6-ori/drivers/scsi/libata-core.c libata-dev-2.6/drivers/scsi/libata-core.c
--- libata-dev-2.6-ori/drivers/scsi/libata-core.c 2004-12-15 16:10:30.000000000 +0800
+++ libata-dev-2.6/drivers/scsi/libata-core.c 2004-12-15 16:15:01.000000000 +0800
@@ -1947,7 +1947,24 @@
if (idx)
ap->prd[idx - 1].flags_len |= cpu_to_le32(ATA_PRD_EOT);
}
+/**
+ * ata_check_atapi_dma - Check whether ATAPI DMA can be supported
+ * @qc: Metadata associated with taskfile to check
+ *
+ * LOCKING:
+ * RETURNS: 0 when ATAPI DMA can be used
+ * nonzero otherwise
+ */
+int ata_check_atapi_dma(struct ata_queued_cmd *qc)
+{
+ struct ata_port *ap = qc->ap;
+ int rc = 1; /* Turn off ATAPI DMA by default */
+
+ if (ap->ops->check_atapi_dma)
+ rc = ap->ops->check_atapi_dma(qc);
+ return rc;
+}
/**
* ata_qc_prep - Prepare taskfile for submission
* @qc: Metadata associated with taskfile to be prepared
diff -Nru libata-dev-2.6-ori/drivers/scsi/libata.h libata-dev-2.6/drivers/scsi/libata.h
--- libata-dev-2.6-ori/drivers/scsi/libata.h 2004-11-30 12:52:28.000000000 +0800
+++ libata-dev-2.6/drivers/scsi/libata.h 2004-12-15 16:36:55.000000000 +0800
@@ -38,6 +38,7 @@
extern struct ata_queued_cmd *ata_qc_new_init(struct ata_port *ap,
struct ata_device *dev);
extern int ata_qc_issue(struct ata_queued_cmd *qc);
+extern int ata_check_atapi_dma(struct ata_queued_cmd *qc);
extern void ata_dev_select(struct ata_port *ap, unsigned int device,
unsigned int wait, unsigned int can_sleep);
extern void ata_tf_to_host_nolock(struct ata_port *ap, struct ata_taskfile *tf);
diff -Nru libata-dev-2.6-ori/drivers/scsi/libata-scsi.c libata-dev-2.6/drivers/scsi/libata-scsi.c
--- libata-dev-2.6-ori/drivers/scsi/libata-scsi.c 2004-11-30 12:52:28.000000000 +0800
+++ libata-dev-2.6/drivers/scsi/libata-scsi.c 2004-12-15 16:15:59.000000000 +0800
@@ -1558,6 +1558,11 @@
int using_pio = (dev->flags & ATA_DFLAG_PIO);
int nodata = (cmd->sc_data_direction == SCSI_DATA_NONE);
+ if (!using_pio)
+ /* Check whether ATAPI DMA is safe */
+ if (ata_check_atapi_dma(qc))
+ using_pio = 1;
+
memcpy(&qc->cdb, scsicmd, qc->ap->cdb_len);
qc->complete_fn = atapi_qc_complete;
diff -Nru libata-dev-2.6-ori/drivers/scsi/pata_pdc2027x.c libata-dev-2.6/drivers/scsi/pata_pdc2027x.c
--- libata-dev-2.6-ori/drivers/scsi/pata_pdc2027x.c 2004-11-30 12:52:28.000000000 +0800
+++ libata-dev-2.6/drivers/scsi/pata_pdc2027x.c 2004-12-15 16:21:00.000000000 +0800
@@ -29,7 +29,7 @@
#include <asm/io.h>
#define DRV_NAME "pata_pdc2027x"
-#define DRV_VERSION "0.53"
+#define DRV_VERSION "0.54"
#undef PDC_DEBUG
#ifdef PDC_DEBUG
@@ -51,6 +51,7 @@
static void pdc2027x_phy_reset(struct ata_port *ap);
static void pdc2027x_set_piomode(struct ata_port *ap, struct ata_device *adev);
static void pdc2027x_set_dmamode(struct ata_port *ap, struct ata_device *adev);
+static int pdc2027x_check_atapi_dma(struct ata_queued_cmd *qc);
/*
* ATA Timing Tables based on 133MHz controller clock.
@@ -141,6 +142,7 @@
.phy_reset = pdc2027x_phy_reset,
+ .check_atapi_dma = pdc2027x_check_atapi_dma,
.bmdma_setup = ata_bmdma_setup,
.bmdma_start = ata_bmdma_start,
.qc_prep = ata_qc_prep,
@@ -377,6 +379,27 @@
}
}
/**
+ * pdc2027x_check_atapi_dma - Check whether ATAPI DMA can be supported for this command
+ * @qc: Metadata associated with taskfile to check
+ *
+ * LOCKING:
+ * None (inherited from caller).
+ *
+ * RETURNS: 0 when ATAPI DMA can be used
+ * 1 otherwise
+ */
+static int pdc2027x_check_atapi_dma(struct ata_queued_cmd *qc)
+{
+ struct scsi_cmnd *cmd = qc->scsicmd;
+ int rc = 0;
+
+ /* pdc2027x can only do ATAPI DMA for specific buffer size */
+ if (cmd->request_bufflen % 256)
+ rc = 1;
+
+ return rc;
+}
+/**
* adjust_pll - Adjust the PLL input clock in Hz.
*
* @pdc_controller: controller specific information
diff -Nru libata-dev-2.6-ori/include/linux/libata.h libata-dev-2.6/include/linux/libata.h
--- libata-dev-2.6-ori/include/linux/libata.h 2004-11-30 12:52:42.000000000 +0800
+++ libata-dev-2.6/include/linux/libata.h 2004-12-15 16:17:41.000000000 +0800
@@ -339,6 +339,8 @@
void (*phy_reset) (struct ata_port *ap);
void (*post_set_mode) (struct ata_port *ap);
+ int (*check_atapi_dma) (struct ata_queued_cmd *qc);
+
void (*bmdma_setup) (struct ata_queued_cmd *qc);
void (*bmdma_start) (struct ata_queued_cmd *qc);
next reply other threads:[~2004-12-15 10:05 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-12-15 10:05 Albert Lee [this message]
-- strict thread matches above, loose matches on Subject: below --
2004-12-16 5:28 [PATCH 3/3] libata - Query the driver for ATAPI DMA support Albert Lee
2004-12-17 20:01 ` Bartlomiej Zolnierkiewicz
2004-12-27 20:29 ` Jeff Garzik
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