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Commit c07a9c49 authored by Mikael Pettersson's avatar Mikael Pettersson Committed by Jeff Garzik
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sata_promise: fix hardreset hotplug events, take 2 



A Promise SATA controller will signal hotplug events when a hard
reset (COMRESET) is done on a port. These events aren't masked by
the driver, and the unexpected interrupts will cause a sequence
of failed reset attempts util libata's EH finally gives up.

This has not been a common problem so far, but the pending libata
hardreset-by-default changes makes it a critical issue.

The solution is to disable hotplug events before a reset, and to
reenable them afterwards. (Promise's driver does this too.)

This patch adds SATA-specific versions of ->freeze() and ->thaw()
that also disable and enable hotplug events. PATA ports continue
to use the old versions of ->freeze() and ->thaw().

Accesses to the hotplug register must be serialised via host->lock.
We rely on ap->lock == &ap->host->lock and that libata takes this
lock before ->freeze() and ->thaw(). Document this requirement.
The interrupt handler is adjusted so its hotplug register accesses
are inside the region protected by host->lock.

Tested on various chips (SATA300TX4, SATA300TX2plus, SATAII150TX4,
FastTrack TX4000) with various combinations of SATA and PATA disks,
with and without the pending hardreset-by-default changes.

Signed-off-by: default avatarMikael Pettersson <mikpe@it.uu.se>
Acked-by: default avatarTejun Heo <htejun@gmail.com>
Signed-off-by: default avatarJeff Garzik <jeff@garzik.org>
parent dda7aba1

drivers/ata/sata_promise.c

+88 −21
Original line number Diff line number Diff line
@@ -46,7 +46,7 @@ 
#include "sata_promise.h"



#define DRV_NAME	"sata_promise"

#define DRV_VERSION	"2.11"

#define DRV_VERSION	"2.12"



enum {

	PDC_MAX_PORTS		= 4,
@@ -145,7 +145,9 @@ static int pdc_old_sata_check_atapi_dma(struct ata_queued_cmd *qc); 
static void pdc_irq_clear(struct ata_port *ap);

static unsigned int pdc_qc_issue_prot(struct ata_queued_cmd *qc);

static void pdc_freeze(struct ata_port *ap);

static void pdc_sata_freeze(struct ata_port *ap);

static void pdc_thaw(struct ata_port *ap);

static void pdc_sata_thaw(struct ata_port *ap);

static void pdc_pata_error_handler(struct ata_port *ap);

static void pdc_sata_error_handler(struct ata_port *ap);

static void pdc_post_internal_cmd(struct ata_queued_cmd *qc);
@@ -180,8 +182,8 @@ static const struct ata_port_operations pdc_sata_ops = { 


	.qc_prep		= pdc_qc_prep,

	.qc_issue		= pdc_qc_issue_prot,

	.freeze			= pdc_freeze,

	.thaw			= pdc_thaw,

	.freeze			= pdc_sata_freeze,

	.thaw			= pdc_sata_thaw,

	.error_handler		= pdc_sata_error_handler,

	.post_internal_cmd	= pdc_post_internal_cmd,

	.cable_detect		= pdc_sata_cable_detect,
@@ -205,8 +207,8 @@ static const struct ata_port_operations pdc_old_sata_ops = { 


	.qc_prep		= pdc_qc_prep,

	.qc_issue		= pdc_qc_issue_prot,

	.freeze			= pdc_freeze,

	.thaw			= pdc_thaw,

	.freeze			= pdc_sata_freeze,

	.thaw			= pdc_sata_thaw,

	.error_handler		= pdc_sata_error_handler,

	.post_internal_cmd	= pdc_post_internal_cmd,

	.cable_detect		= pdc_sata_cable_detect,
@@ -631,6 +633,41 @@ static void pdc_qc_prep(struct ata_queued_cmd *qc) 
	}

}



static int pdc_is_sataii_tx4(unsigned long flags)

{

	const unsigned long mask = PDC_FLAG_GEN_II | PDC_FLAG_4_PORTS;

	return (flags & mask) == mask;

}



static unsigned int pdc_port_no_to_ata_no(unsigned int port_no,

					  int is_sataii_tx4)

{

	static const unsigned char sataii_tx4_port_remap[4] = { 3, 1, 0, 2};

	return is_sataii_tx4 ? sataii_tx4_port_remap[port_no] : port_no;

}



static unsigned int pdc_sata_nr_ports(const struct ata_port *ap)

{

	return (ap->flags & PDC_FLAG_4_PORTS) ? 4 : 2;

}



static unsigned int pdc_sata_ata_port_to_ata_no(const struct ata_port *ap)

{

	const struct ata_host *host = ap->host;

	unsigned int nr_ports = pdc_sata_nr_ports(ap);

	unsigned int i;



	for(i = 0; i < nr_ports && host->ports[i] != ap; ++i)

		;

	BUG_ON(i >= nr_ports);

	return pdc_port_no_to_ata_no(i, pdc_is_sataii_tx4(ap->flags));

}



static unsigned int pdc_sata_hotplug_offset(const struct ata_port *ap)

{

	return (ap->flags & PDC_FLAG_GEN_II) ? PDC2_SATA_PLUG_CSR : PDC_SATA_PLUG_CSR;

}



static void pdc_freeze(struct ata_port *ap)

{

	void __iomem *mmio = ap->ioaddr.cmd_addr;
@@ -643,6 +680,29 @@ static void pdc_freeze(struct ata_port *ap) 
	readl(mmio + PDC_CTLSTAT); /* flush */

}



static void pdc_sata_freeze(struct ata_port *ap)

{

	struct ata_host *host = ap->host;

	void __iomem *host_mmio = host->iomap[PDC_MMIO_BAR];

	unsigned int hotplug_offset = pdc_sata_hotplug_offset(ap);

	unsigned int ata_no = pdc_sata_ata_port_to_ata_no(ap);

	u32 hotplug_status;



	/* Disable hotplug events on this port.

	 *

	 * Locking:

	 * 1) hotplug register accesses must be serialised via host->lock

	 * 2) ap->lock == &ap->host->lock

	 * 3) ->freeze() and ->thaw() are called with ap->lock held

	 */

	hotplug_status = readl(host_mmio + hotplug_offset);

	hotplug_status |= 0x11 << (ata_no + 16);

	writel(hotplug_status, host_mmio + hotplug_offset);

	readl(host_mmio + hotplug_offset); /* flush */



	pdc_freeze(ap);

}



static void pdc_thaw(struct ata_port *ap)

{

	void __iomem *mmio = ap->ioaddr.cmd_addr;
@@ -658,6 +718,26 @@ static void pdc_thaw(struct ata_port *ap) 
	readl(mmio + PDC_CTLSTAT); /* flush */

}



static void pdc_sata_thaw(struct ata_port *ap)

{

	struct ata_host *host = ap->host;

	void __iomem *host_mmio = host->iomap[PDC_MMIO_BAR];

	unsigned int hotplug_offset = pdc_sata_hotplug_offset(ap);

	unsigned int ata_no = pdc_sata_ata_port_to_ata_no(ap);

	u32 hotplug_status;



	pdc_thaw(ap);



	/* Enable hotplug events on this port.

	 * Locking: see pdc_sata_freeze().

	 */

	hotplug_status = readl(host_mmio + hotplug_offset);

	hotplug_status |= 0x11 << ata_no;

	hotplug_status &= ~(0x11 << (ata_no + 16));

	writel(hotplug_status, host_mmio + hotplug_offset);

	readl(host_mmio + hotplug_offset); /* flush */

}



static void pdc_common_error_handler(struct ata_port *ap, ata_reset_fn_t hardreset)

{

	if (!(ap->pflags & ATA_PFLAG_FROZEN))
@@ -765,19 +845,6 @@ static void pdc_irq_clear(struct ata_port *ap) 
	readl(mmio + PDC_INT_SEQMASK);

}



static int pdc_is_sataii_tx4(unsigned long flags)

{

	const unsigned long mask = PDC_FLAG_GEN_II | PDC_FLAG_4_PORTS;

	return (flags & mask) == mask;

}



static unsigned int pdc_port_no_to_ata_no(unsigned int port_no,

					  int is_sataii_tx4)

{

	static const unsigned char sataii_tx4_port_remap[4] = { 3, 1, 0, 2};

	return is_sataii_tx4 ? sataii_tx4_port_remap[port_no] : port_no;

}



static irqreturn_t pdc_interrupt(int irq, void *dev_instance)

{

	struct ata_host *host = dev_instance;
@@ -799,6 +866,8 @@ static irqreturn_t pdc_interrupt(int irq, void *dev_instance) 


	mmio_base = host->iomap[PDC_MMIO_BAR];



	spin_lock(&host->lock);



	/* read and clear hotplug flags for all ports */

	if (host->ports[0]->flags & PDC_FLAG_GEN_II)

		hotplug_offset = PDC2_SATA_PLUG_CSR;
@@ -814,11 +883,9 @@ static irqreturn_t pdc_interrupt(int irq, void *dev_instance) 


	if (mask == 0xffffffff && hotplug_status == 0) {

		VPRINTK("QUICK EXIT 2\n");

		return IRQ_NONE;

		goto done_irq;

	}



	spin_lock(&host->lock);



	mask &= 0xffff;		/* only 16 tags possible */

	if (mask == 0 && hotplug_status == 0) {

		VPRINTK("QUICK EXIT 3\n");