diff options
| -rw-r--r-- | drivers/parport/parport_pc.c | 46 | ||||
| -rw-r--r-- | include/linux/parport_pc.h | 3 |
2 files changed, 32 insertions, 17 deletions
diff --git a/drivers/parport/parport_pc.c b/drivers/parport/parport_pc.c index 9daaaaa305e6..ad49fd356c7b 100644 --- a/drivers/parport/parport_pc.c +++ b/drivers/parport/parport_pc.c @@ -106,15 +106,22 @@ static int pnp_registered_parport; static void frob_econtrol(struct parport *pb, unsigned char m, unsigned char v) { + const struct parport_pc_private *priv = pb->physport->private_data; + unsigned char ecr_writable = priv->ecr_writable; unsigned char ectr = 0; + unsigned char new; if (m != 0xff) ectr = inb(ECONTROL(pb)); - pr_debug("frob_econtrol(%02x,%02x): %02x -> %02x\n", - m, v, ectr, (ectr & ~m) ^ v); + new = (ectr & ~m) ^ v; + if (ecr_writable) + /* All known users of the ECR mask require bit 0 to be set. */ + new = (new & ecr_writable) | 1; - outb((ectr & ~m) ^ v, ECONTROL(pb)); + pr_debug("frob_econtrol(%02x,%02x): %02x -> %02x\n", m, v, ectr, new); + + outb(new, ECONTROL(pb)); } static inline void frob_set_mode(struct parport *p, int mode) @@ -1479,21 +1486,24 @@ static int parport_ECR_present(struct parport *pb) struct parport_pc_private *priv = pb->private_data; unsigned char r = 0xc; - outb(r, CONTROL(pb)); - if ((inb(ECONTROL(pb)) & 0x3) == (r & 0x3)) { - outb(r ^ 0x2, CONTROL(pb)); /* Toggle bit 1 */ + if (!priv->ecr_writable) { + outb(r, CONTROL(pb)); + if ((inb(ECONTROL(pb)) & 0x3) == (r & 0x3)) { + outb(r ^ 0x2, CONTROL(pb)); /* Toggle bit 1 */ - r = inb(CONTROL(pb)); - if ((inb(ECONTROL(pb)) & 0x2) == (r & 0x2)) - goto no_reg; /* Sure that no ECR register exists */ - } + r = inb(CONTROL(pb)); + if ((inb(ECONTROL(pb)) & 0x2) == (r & 0x2)) + /* Sure that no ECR register exists */ + goto no_reg; + } - if ((inb(ECONTROL(pb)) & 0x3) != 0x1) - goto no_reg; + if ((inb(ECONTROL(pb)) & 0x3) != 0x1) + goto no_reg; - ECR_WRITE(pb, 0x34); - if (inb(ECONTROL(pb)) != 0x35) - goto no_reg; + ECR_WRITE(pb, 0x34); + if (inb(ECONTROL(pb)) != 0x35) + goto no_reg; + } priv->ecr = 1; outb(0xc, CONTROL(pb)); @@ -2005,7 +2015,8 @@ static struct parport *__parport_pc_probe_port(unsigned long int base, int irq, int dma, struct device *dev, int irqflags, - unsigned int mode_mask) + unsigned int mode_mask, + unsigned char ecr_writable) { struct parport_pc_private *priv; struct parport_operations *ops; @@ -2054,6 +2065,7 @@ static struct parport *__parport_pc_probe_port(unsigned long int base, priv->ctr = 0xc; priv->ctr_writable = ~0x10; priv->ecr = 0; + priv->ecr_writable = ecr_writable; priv->fifo_depth = 0; priv->dma_buf = NULL; priv->dma_handle = 0; @@ -2256,7 +2268,7 @@ struct parport *parport_pc_probe_port(unsigned long int base, int irqflags) { return __parport_pc_probe_port(base, base_hi, irq, dma, - dev, irqflags, 0); + dev, irqflags, 0, 0); } EXPORT_SYMBOL(parport_pc_probe_port); diff --git a/include/linux/parport_pc.h b/include/linux/parport_pc.h index 3d6fc576d6a1..f1ec5c10c3b3 100644 --- a/include/linux/parport_pc.h +++ b/include/linux/parport_pc.h @@ -26,6 +26,9 @@ struct parport_pc_private { /* Whether or not there's an ECR. */ int ecr; + /* Bitmask of writable ECR bits. */ + unsigned char ecr_writable; + /* Number of PWords that FIFO will hold. */ int fifo_depth; |