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Commit f75d4a23 authored by Bartlomiej Zolnierkiewicz's avatar Bartlomiej Zolnierkiewicz Committed by David S. Miller
Browse files

icside: bring back ->maskproc method 



Bring back ->maskproc method since it is still needed for proper operation,
as noticed by Russell King:

> This change is bogus.
>
>         writeb(0, base + ICS_ARCIN_V6_INTROFFSET_1);
>         readb(base + ICS_ARCIN_V6_INTROFFSET_2);
>
>         writeb(0, base + ICS_ARCIN_V6_INTROFFSET_2);
>         readb(base + ICS_ARCIN_V6_INTROFFSET_1);
>
> This sequence of code does:
>
> 1. enable interrupt 1
> 2. disable interrupt 2
> 3. enable interrupt 2
> 4. disable interrupt 1
>
> which results in the interrupt for the second channel being enabled -
> leaving channel 1 blocked.
>
> Firstly, icside shares its two IDE channels with one DMA engine - so it's
> a simplex interface.  IDE supports those (or did when the code was written)
> serializing requests between the two interfaces.  libata does not.
>
> Secondly, the interrupt lines on icside float when there's no drive connected
> or when the drive has its NIEN bit set, which means that you get spurious
> screaming interrupts which can kill off all expansion card interrupts on
> the machine unless you disable the channel interrupt on the card.
>
> Since libata can not serialize the operation of the two channels like IDE
> can, the libata version of the icside driver does not contain the interrupt
> stearing logic.  Instead, it looks at the status after reset, and if
> nothing was found on that channel, it masks the interrupt from that
> channel.

This patch reverts changes done in commit dff8817b (I became confused due to
non-standard & undocumented ->maskproc method, anyway sorry about that).

Noticed-by: default avatarRussell King <rmk@arm.linux.org.uk>
Signed-off-by: default avatarBartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 4cd7d924

drivers/ide/icside.c

+60 −4
Original line number Diff line number Diff line
@@ -65,6 +65,8 @@ static struct cardinfo icside_cardinfo_v6_2 = { 
};



struct icside_state {

	unsigned int channel;

	unsigned int enabled;

	void __iomem *irq_port;

	void __iomem *ioc_base;

	unsigned int sel;
@@ -114,11 +116,18 @@ static void icside_irqenable_arcin_v6 (struct expansion_card *ec, int irqnr) 
	struct icside_state *state = ec->irq_data;

	void __iomem *base = state->irq_port;



	state->enabled = 1;



	switch (state->channel) {

	case 0:

		writeb(0, base + ICS_ARCIN_V6_INTROFFSET_1);

		readb(base + ICS_ARCIN_V6_INTROFFSET_2);



		break;

	case 1:

		writeb(0, base + ICS_ARCIN_V6_INTROFFSET_2);

		readb(base + ICS_ARCIN_V6_INTROFFSET_1);

		break;

	}

}



/* Prototype: icside_irqdisable_arcin_v6 (struct expansion_card *ec, int irqnr)
@@ -128,6 +137,8 @@ static void icside_irqdisable_arcin_v6 (struct expansion_card *ec, int irqnr) 
{

	struct icside_state *state = ec->irq_data;



	state->enabled = 0;



	readb(state->irq_port + ICS_ARCIN_V6_INTROFFSET_1);

	readb(state->irq_port + ICS_ARCIN_V6_INTROFFSET_2);

}
@@ -149,6 +160,44 @@ static const expansioncard_ops_t icside_ops_arcin_v6 = { 
	.irqpending	= icside_irqpending_arcin_v6,

};



/*

 * Handle routing of interrupts.  This is called before

 * we write the command to the drive.

 */

static void icside_maskproc(ide_drive_t *drive, int mask)

{

	ide_hwif_t *hwif = drive->hwif;

	struct expansion_card *ec = ECARD_DEV(hwif->dev);

	struct icside_state *state = ecard_get_drvdata(ec);

	unsigned long flags;



	local_irq_save(flags);



	state->channel = hwif->channel;



	if (state->enabled && !mask) {

		switch (hwif->channel) {

		case 0:

			writeb(0, state->irq_port + ICS_ARCIN_V6_INTROFFSET_1);

			readb(state->irq_port + ICS_ARCIN_V6_INTROFFSET_2);

			break;

		case 1:

			writeb(0, state->irq_port + ICS_ARCIN_V6_INTROFFSET_2);

			readb(state->irq_port + ICS_ARCIN_V6_INTROFFSET_1);

			break;

		}

	} else {

		readb(state->irq_port + ICS_ARCIN_V6_INTROFFSET_2);

		readb(state->irq_port + ICS_ARCIN_V6_INTROFFSET_1);

	}



	local_irq_restore(flags);

}



static const struct ide_port_ops icside_v6_no_dma_port_ops = {

	.maskproc		= icside_maskproc,

};



#ifdef CONFIG_BLK_DEV_IDEDMA_ICS

/*

 * SG-DMA support.
@@ -228,6 +277,7 @@ static void icside_set_dma_mode(ide_drive_t *drive, const u8 xfer_mode) 


static const struct ide_port_ops icside_v6_port_ops = {

	.set_dma_mode		= icside_set_dma_mode,

	.maskproc		= icside_maskproc,

};



static void icside_dma_host_set(ide_drive_t *drive, int on)
@@ -271,6 +321,11 @@ static int icside_dma_setup(ide_drive_t *drive, struct ide_cmd *cmd) 
	 */

	BUG_ON(dma_channel_active(ec->dma));



	/*

	 * Ensure that we have the right interrupt routed.

	 */

	icside_maskproc(drive, 0);



	/*

	 * Route the DMA signals to the correct interface.

	 */
@@ -399,6 +454,7 @@ icside_register_v5(struct icside_state *state, struct expansion_card *ec) 


static const struct ide_port_info icside_v6_port_info __initdata = {

	.init_dma		= icside_dma_off_init,

	.port_ops		= &icside_v6_no_dma_port_ops,

	.dma_ops		= &icside_v6_dma_ops,

	.host_flags		= IDE_HFLAG_SERIALIZE | IDE_HFLAG_MMIO,

	.mwdma_mask		= ATA_MWDMA2,