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 dff8817 (I became confused due to
non-standard & undocumented ->maskproc method, anyway sorry about that).
Noticed-by: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/ide/icside.c b/drivers/ide/icside.c
index 0f67f1a..d7e6f09 100644
--- a/drivers/ide/icside.c
+++ b/drivers/ide/icside.c
@@ -65,6 +65,8 @@
};
struct icside_state {
+ unsigned int channel;
+ unsigned int enabled;
void __iomem *irq_port;
void __iomem *ioc_base;
unsigned int sel;
@@ -114,11 +116,18 @@
struct icside_state *state = ec->irq_data;
void __iomem *base = state->irq_port;
- writeb(0, base + ICS_ARCIN_V6_INTROFFSET_1);
- readb(base + ICS_ARCIN_V6_INTROFFSET_2);
+ state->enabled = 1;
- writeb(0, base + ICS_ARCIN_V6_INTROFFSET_2);
- readb(base + ICS_ARCIN_V6_INTROFFSET_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 @@
{
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 @@
.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 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)
@@ -272,6 +322,11 @@
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.
*/
writeb(state->sel | hwif->channel, state->ioc_base);
@@ -399,6 +454,7 @@
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,
