Messages in this thread Patch in this message | | | Date | Wed, 16 Nov 2022 21:35:56 +0000 (GMT) | From | "Maciej W. Rozycki" <> | Subject | [PATCH 2/6] parport_pc: Let chipset drivers mask unsupported modes |
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Rename `parport_pc_probe_port' to `__parport_pc_probe_port' and add a `mode_mask' parameter so that callers can specify a mask of unsupported modes to exclude even if mode probing seems to indicate otherwise. Add a `parport_pc_probe_port' wrapper with an implicit mask of 0 for the current callers to use.
No functional change at this point, but the configuration of data write handlers is now no longer intertwined with determination and reporting of available modes.
Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk> --- drivers/parport/parport_pc.c | 45 +++++++++++++++++++++++++++++++------------ 1 file changed, 33 insertions(+), 12 deletions(-)
linux-parport-pc-mode-mask.diff Index: linux-macro/drivers/parport/parport_pc.c =================================================================== --- linux-macro.orig/drivers/parport/parport_pc.c +++ linux-macro/drivers/parport/parport_pc.c @@ -2000,11 +2000,12 @@ static int parport_dma_probe(struct parp static LIST_HEAD(ports_list); static DEFINE_SPINLOCK(ports_lock); -struct parport *parport_pc_probe_port(unsigned long int base, - unsigned long int base_hi, - int irq, int dma, - struct device *dev, - int irqflags) +static struct parport *__parport_pc_probe_port(unsigned long int base, + unsigned long int base_hi, + int irq, int dma, + struct device *dev, + int irqflags, + unsigned int mode_mask) { struct parport_pc_private *priv; struct parport_operations *ops; @@ -2116,18 +2117,28 @@ struct parport *parport_pc_probe_port(un p->dma != PARPORT_DMA_NOFIFO && priv->fifo_depth > 0 && p->irq != PARPORT_IRQ_NONE) { p->modes |= PARPORT_MODE_ECP | PARPORT_MODE_COMPAT; + if (p->dma != PARPORT_DMA_NONE) + p->modes |= PARPORT_MODE_DMA; + } else + /* We can't use the DMA channel after all. */ + p->dma = PARPORT_DMA_NONE; +#endif /* Allowed to use FIFO/DMA */ + + p->modes &= ~mode_mask; + +#ifdef CONFIG_PARPORT_PC_FIFO + if ((p->modes & PARPORT_MODE_COMPAT) != 0) p->ops->compat_write_data = parport_pc_compat_write_block_pio; #ifdef CONFIG_PARPORT_1284 + if ((p->modes & PARPORT_MODE_ECP) != 0) p->ops->ecp_write_data = parport_pc_ecp_write_block_pio; -#endif /* IEEE 1284 support */ - if (p->dma != PARPORT_DMA_NONE) { +#endif + if ((p->modes & (PARPORT_MODE_ECP | PARPORT_MODE_COMPAT)) != 0) { + if ((p->modes & PARPORT_MODE_DMA) != 0) pr_cont(", dma %d", p->dma); - p->modes |= PARPORT_MODE_DMA; - } else + else pr_cont(", using FIFO"); - } else - /* We can't use the DMA channel after all. */ - p->dma = PARPORT_DMA_NONE; + } #endif /* Allowed to use FIFO/DMA */ pr_cont(" ["); @@ -2237,6 +2248,16 @@ do { \ platform_device_unregister(pdev); return NULL; } + +struct parport *parport_pc_probe_port(unsigned long int base, + unsigned long int base_hi, + int irq, int dma, + struct device *dev, + int irqflags) +{ + return __parport_pc_probe_port(base, base_hi, irq, dma, + dev, irqflags, 0); +} EXPORT_SYMBOL(parport_pc_probe_port); void parport_pc_unregister_port(struct parport *p)
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