Commit 398e0782 authored by Tejun Heo's avatar Tejun Heo Committed by Jeff Garzik
Browse files

libata-acpi: implement dev->gtf_cache and evaluate _GTF right after _STM during resume 



On certain implementations, _GTF evaluation depends on preceding _STM
and both can be pretty picky about the configuration.  Using _GTM
result cached during controller initialization satisfies the most
neurotic _STM implementation.  However, libata evaluates _GTF after
reset during device configuration and the hardware state can be
different from what _GTF expects and can cause evaluation failure.

This patch adds dev->gtf_cache and updates ata_dev_get_GTF() such that
it uses the cached value if available.  Cache is cleared with a call
to ata_acpi_clear_gtf().

Because for SATA ACPI nodes _GTF must be evaluated after _SDD which
can't be done till IDENTIFY is complete, _GTF caching from
ata_acpi_on_resume() is used only for IDE ACPI nodes.

Signed-off-by: default avatarTejun Heo <htejun@gmail.com>
Signed-off-by: default avatarJeff Garzik <jeff@garzik.org>
parent c05e6ff0

drivers/ata/libata-acpi.c

+49 −20
Original line number Diff line number Diff line
@@ -41,6 +41,12 @@ static int is_pci_dev(struct device *dev) 
	return (dev->bus == &pci_bus_type);

}



static void ata_acpi_clear_gtf(struct ata_device *dev)

{

	kfree(dev->gtf_cache);

	dev->gtf_cache = NULL;

}



/**

 * ata_acpi_associate_sata_port - associate SATA port with ACPI objects

 * @ap: target SATA port
@@ -327,7 +333,6 @@ EXPORT_SYMBOL_GPL(ata_acpi_stm); 
 * ata_dev_get_GTF - get the drive bootup default taskfile settings

 * @dev: target ATA device

 * @gtf: output parameter for buffer containing _GTF taskfile arrays

 * @ptr_to_free: pointer which should be freed

 *

 * This applies to both PATA and SATA drives.

 *
@@ -344,8 +349,7 @@ EXPORT_SYMBOL_GPL(ata_acpi_stm); 
 * Number of taskfiles on success, 0 if _GTF doesn't exist or doesn't

 * contain valid data.

 */

static int ata_dev_get_GTF(struct ata_device *dev, struct ata_acpi_gtf **gtf,

			   void **ptr_to_free)

static int ata_dev_get_GTF(struct ata_device *dev, struct ata_acpi_gtf **gtf)

{

	struct ata_port *ap = dev->link->ap;

	acpi_status status;
@@ -353,6 +357,12 @@ static int ata_dev_get_GTF(struct ata_device *dev, struct ata_acpi_gtf **gtf, 
	union acpi_object *out_obj;

	int rc = 0;



	/* if _GTF is cached, use the cached value */

	if (dev->gtf_cache) {

		out_obj = dev->gtf_cache;

		goto done;

	}



	/* set up output buffer */

	output.length = ACPI_ALLOCATE_BUFFER;

	output.pointer = NULL;	/* ACPI-CA sets this; save/free it later */
@@ -363,6 +373,7 @@ static int ata_dev_get_GTF(struct ata_device *dev, struct ata_acpi_gtf **gtf, 


	/* _GTF has no input parameters */

	status = acpi_evaluate_object(dev->acpi_handle, "_GTF", NULL, &output);

	out_obj = dev->gtf_cache = output.pointer;



	if (ACPI_FAILURE(status)) {

		if (status != AE_NOT_FOUND) {
@@ -383,7 +394,6 @@ static int ata_dev_get_GTF(struct ata_device *dev, struct ata_acpi_gtf **gtf, 
		goto out_free;

	}



	out_obj = output.pointer;

	if (out_obj->type != ACPI_TYPE_BUFFER) {

		ata_dev_printk(dev, KERN_WARNING,

			       "_GTF unexpected object type 0x%x\n",
@@ -398,18 +408,19 @@ static int ata_dev_get_GTF(struct ata_device *dev, struct ata_acpi_gtf **gtf, 
		goto out_free;

	}



	*ptr_to_free = out_obj;

	*gtf = (void *)out_obj->buffer.pointer;

 done:

	rc = out_obj->buffer.length / REGS_PER_GTF;



	if (gtf) {

		*gtf = (void *)out_obj->buffer.pointer;

		if (ata_msg_probe(ap))

		ata_dev_printk(dev, KERN_DEBUG, "%s: returning "

			"gtf=%p, gtf_count=%d, ptr_to_free=%p\n",

			__FUNCTION__, *gtf, rc, *ptr_to_free);

			ata_dev_printk(dev, KERN_DEBUG,

				       "%s: returning gtf=%p, gtf_count=%d\n",

				       __FUNCTION__, *gtf, rc);

	}

	return rc;



 out_free:

	kfree(output.pointer);

	ata_acpi_clear_gtf(dev);

	return rc;

}
@@ -533,11 +544,10 @@ static int taskfile_load_raw(struct ata_device *dev, 
static int ata_acpi_exec_tfs(struct ata_device *dev)

{

	struct ata_acpi_gtf *gtf = NULL;

	void *ptr_to_free = NULL;

	int gtf_count, i, rc;



	/* get taskfiles */

	gtf_count = ata_dev_get_GTF(dev, &gtf, &ptr_to_free);

	gtf_count = ata_dev_get_GTF(dev, &gtf);



	/* execute them */

	for (i = 0, rc = 0; i < gtf_count; i++) {
@@ -551,7 +561,7 @@ static int ata_acpi_exec_tfs(struct ata_device *dev) 
			rc = tmp;

	}



	kfree(ptr_to_free);

	ata_acpi_clear_gtf(dev);



	if (rc == 0)

		return gtf_count;
@@ -644,14 +654,32 @@ void ata_acpi_on_resume(struct ata_port *ap) 
	const struct ata_acpi_gtm *gtm = ata_acpi_init_gtm(ap);

	struct ata_device *dev;



	if (ap->acpi_handle && gtm) {

		/* _GTM valid */



		/* restore timing parameters */

	if (ap->acpi_handle && gtm)

		ata_acpi_stm(ap, gtm);



	/* schedule _GTF */

	ata_link_for_each_dev(dev, &ap->link)

		/* _GTF should immediately follow _STM so that it can

		 * use values set by _STM.  Cache _GTF result and

		 * schedule _GTF.

		 */

		ata_link_for_each_dev(dev, &ap->link) {

			ata_acpi_clear_gtf(dev);

			if (ata_dev_get_GTF(dev, NULL) >= 0)

				dev->flags |= ATA_DFLAG_ACPI_PENDING;

		}

	} else {

		/* SATA _GTF needs to be evaulated after _SDD and

		 * there's no reason to evaluate IDE _GTF early

		 * without _STM.  Clear cache and schedule _GTF.

		 */

		ata_link_for_each_dev(dev, &ap->link) {

			ata_acpi_clear_gtf(dev);

			dev->flags |= ATA_DFLAG_ACPI_PENDING;

		}

	}

}



/**

 * ata_acpi_on_devcfg - ATA ACPI hook called on device donfiguration
@@ -735,4 +763,5 @@ int ata_acpi_on_devcfg(struct ata_device *dev) 
 */

void ata_acpi_on_disable(struct ata_device *dev)

{

	ata_acpi_clear_gtf(dev);

}

include/linux/libata.h

+1 −0
Original line number Diff line number Diff line
@@ -498,6 +498,7 @@ struct ata_device { 
	struct scsi_device	*sdev;		/* attached SCSI device */

#ifdef CONFIG_ATA_ACPI

	acpi_handle		acpi_handle;

	union acpi_object	*gtf_cache;

#endif

	/* n_sector is used as CLEAR_OFFSET, read comment above CLEAR_OFFSET */

	u64			n_sectors;	/* size of device, if ATA */

CRA Git | Maintained and supported by SUSTech CRA and CCSE