Re: [PATCH 1/2] parport: gsc: remove DMA leftover code

From: Helge Deller
Date: Thu Aug 03 2023 - 04:17:20 EST


On 7/26/23 17:09, Arnd Bergmann wrote:
From: Arnd Bergmann <arnd@xxxxxxxx>

This driver does not actually work with DMA mode, but still tries
to call ISA DMA interface functions that are stubbed out on
parisc, resulting in a W=1 build warning:

drivers/parport/parport_gsc.c: In function 'parport_remove_chip':
drivers/parport/parport_gsc.c:389:20: warning: suggest braces around empty body in an 'if' statement [-Wempty-body]
389 | free_dma(p->dma);

Remove the corresponding code as a prerequisite for turning on -Wempty-body
by default in all kernels.

Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>

Thanks Arnd!

I've added it to the parisc for-next git tree.

Helge

---
drivers/parport/parport_gsc.c | 28 ++++------------------------
drivers/parport/parport_gsc.h | 7 -------
2 files changed, 4 insertions(+), 31 deletions(-)

diff --git a/drivers/parport/parport_gsc.c b/drivers/parport/parport_gsc.c
index 0dcc497b0449a..5e4475254bd0a 100644
--- a/drivers/parport/parport_gsc.c
+++ b/drivers/parport/parport_gsc.c
@@ -28,7 +28,6 @@
#include <linux/sysctl.h>

#include <asm/io.h>
-#include <asm/dma.h>
#include <linux/uaccess.h>
#include <asm/superio.h>

@@ -226,9 +225,9 @@ static int parport_PS2_supported(struct parport *pb)

/* --- Initialisation code -------------------------------- */

-struct parport *parport_gsc_probe_port(unsigned long base,
+static struct parport *parport_gsc_probe_port(unsigned long base,
unsigned long base_hi, int irq,
- int dma, struct parisc_device *padev)
+ struct parisc_device *padev)
{
struct parport_gsc_private *priv;
struct parport_operations *ops;
@@ -250,12 +249,9 @@ struct parport *parport_gsc_probe_port(unsigned long base,
}
priv->ctr = 0xc;
priv->ctr_writable = 0xff;
- priv->dma_buf = NULL;
- priv->dma_handle = 0;
p->base = base;
p->base_hi = base_hi;
p->irq = irq;
- p->dma = dma;
p->modes = PARPORT_MODE_PCSPP | PARPORT_MODE_SAFEININT;
p->ops = ops;
p->private_data = priv;
@@ -286,17 +282,9 @@ struct parport *parport_gsc_probe_port(unsigned long base,
if (p->irq == PARPORT_IRQ_AUTO) {
p->irq = PARPORT_IRQ_NONE;
}
- if (p->irq != PARPORT_IRQ_NONE) {
+ if (p->irq != PARPORT_IRQ_NONE)
pr_cont(", irq %d", p->irq);

- if (p->dma == PARPORT_DMA_AUTO) {
- p->dma = PARPORT_DMA_NONE;
- }
- }
- if (p->dma == PARPORT_DMA_AUTO) /* To use DMA, giving the irq
- is mandatory (see above) */
- p->dma = PARPORT_DMA_NONE;
-
pr_cont(" [");
#define printmode(x) \
do { \
@@ -321,7 +309,6 @@ do { \
pr_warn("%s: irq %d in use, resorting to polled operation\n",
p->name, p->irq);
p->irq = PARPORT_IRQ_NONE;
- p->dma = PARPORT_DMA_NONE;
}
}

@@ -369,8 +356,7 @@ static int __init parport_init_chip(struct parisc_device *dev)
pr_info("%s: enhanced parport-modes not supported\n", __func__);
}

- p = parport_gsc_probe_port(port, 0, dev->irq,
- /* PARPORT_IRQ_NONE */ PARPORT_DMA_NONE, dev);
+ p = parport_gsc_probe_port(port, 0, dev->irq, dev);
if (p)
parport_count++;
dev_set_drvdata(&dev->dev, p);
@@ -382,16 +368,10 @@ static void __exit parport_remove_chip(struct parisc_device *dev)
{
struct parport *p = dev_get_drvdata(&dev->dev);
if (p) {
- struct parport_gsc_private *priv = p->private_data;
struct parport_operations *ops = p->ops;
parport_remove_port(p);
- if (p->dma != PARPORT_DMA_NONE)
- free_dma(p->dma);
if (p->irq != PARPORT_IRQ_NONE)
free_irq(p->irq, p);
- if (priv->dma_buf)
- dma_free_coherent(&priv->dev->dev, PAGE_SIZE,
- priv->dma_buf, priv->dma_handle);
kfree (p->private_data);
parport_put_port(p);
kfree (ops); /* hope no-one cached it */
diff --git a/drivers/parport/parport_gsc.h b/drivers/parport/parport_gsc.h
index 9301217edf12c..d447a568c2570 100644
--- a/drivers/parport/parport_gsc.h
+++ b/drivers/parport/parport_gsc.h
@@ -63,8 +63,6 @@ struct parport_gsc_private {
int writeIntrThreshold;

/* buffer suitable for DMA, if DMA enabled */
- char *dma_buf;
- dma_addr_t dma_handle;
struct pci_dev *dev;
};

@@ -199,9 +197,4 @@ extern void parport_gsc_inc_use_count(void);

extern void parport_gsc_dec_use_count(void);

-extern struct parport *parport_gsc_probe_port(unsigned long base,
- unsigned long base_hi,
- int irq, int dma,
- struct parisc_device *padev);
-
#endif /* __DRIVERS_PARPORT_PARPORT_GSC_H */