[PATCH 5/6] parport_pc: Add an ECR mask field for PCI devices

From: Maciej W. Rozycki
Date: Wed Nov 16 2022 - 16:36:21 EST


Add a bitmask field specifying writable ECR bits for PCI devices and
apply it via `__parport_pc_probe_port'.

Signed-off-by: Maciej W. Rozycki <macro@xxxxxxxxxxx>
---
drivers/parport/parport_pc.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)

linux-parport-pc-pci-ecr-write.diff
Index: linux-macro/drivers/parport/parport_pc.c
===================================================================
--- linux-macro.orig/drivers/parport/parport_pc.c
+++ linux-macro/drivers/parport/parport_pc.c
@@ -2662,6 +2662,10 @@ static struct parport_pc_pci {
/* Bit field of parport modes to exclude. */
unsigned int mode_mask;

+ /* If non-zero, sets the bitmask of writable ECR bits. In that
+ * case additionally bit 0 will be forcibly set on writes. */
+ unsigned char ecr_writable;
+
/* If set, this is called immediately after pci_enable_device.
* If it returns non-zero, no probing will take place and the
* ports will not be used. */
@@ -2868,7 +2872,8 @@ static int parport_pc_pci_probe(struct p
__parport_pc_probe_port(io_lo, io_hi, irq,
PARPORT_DMA_NONE, &dev->dev,
IRQF_SHARED,
- cards[i].mode_mask, 0);
+ cards[i].mode_mask,
+ cards[i].ecr_writable);
if (data->ports[count])
count++;
}