As a general rule, the kernel must allow probes to fail,
but we should not insert the PL080 driver if it's probe fails.
Signed-off-by: Peter M Pearse <[email protected]>
---
diff -purN arm_amba_pl080/drivers/amba/dma.c
arm_amba_pl080err/drivers/amba/dma.c
--- arm_amba_pl080/drivers/amba/dma.c 2006-10-17 17:14:06.000000000 +0100
+++ arm_amba_pl080err/drivers/amba/dma.c 2006-10-18
08:24:03.000000000 +0100
@@ -116,7 +116,7 @@ static struct dma_ops amba_dma_ops = {
/*
* Initialize the dma channels, as far as we can
*/
-void amba_init_dma(dma_t *channels)
+int amba_init_dma(dma_t *channels)
{
int i;
@@ -135,6 +135,7 @@ void amba_init_dma(dma_t *channels)
channels[i].state = 0;
channels[i].d_ops = &amba_dma_ops;
}
+ return 1;
}
EXPORT_SYMBOL(amba_init_dma);
diff -purN arm_amba_pl080/drivers/amba/pl080.c
arm_amba_pl080err/drivers/amba/pl080.c
--- arm_amba_pl080/drivers/amba/pl080.c 2006-10-17 17:14:20.000000000 +0100
+++ arm_amba_pl080err/drivers/amba/pl080.c 2006-10-18
08:24:03.000000000 +0100
@@ -237,7 +237,11 @@ pl080_extra_ops pl080_ops = {
* Complete the DMA channel initialization
* started by the AMBA DMA code
* - Set the dma ops for the board to call
+ * Since driver registration disregards any probe errors we
+ * store the result to prevent registration of an invalid driver
+ * and possible insertion of an invalid module
*/
+static int probe_err = 0; /* Protected by the device lock */
static int __devinit pl080_probe(struct amba_device *dev, void *id)
{
int ret,i;
@@ -271,19 +275,25 @@ static int __devinit pl080_probe(struct
if(!(pl080.pool = dma_pool_create(pl080_driver.drv.name, (struct
device *)dev,
PL080_MAX_LLIS_SIZE, PL080_ALIGN, PL080_ALLOC))){
- kfree(pl080.chanllis);
ret = -ENOMEM;
- goto out;
+ goto out2;
+ }
+ /* TODO:: Get the parameters from amba_device */
+ if(!pl080_init_dma(dev->chans, dev->dmac_ops)){
+ ret = -EPERM;
+ goto out2;
}
- /* TODO:: Get the parameters from amb_device */
- pl080_init_dma(dev->chans, dev->dmac_ops);
+
pl080_driver.drv.owner = try_find_module(MODULE_NAME);
- return ret;
+ return (probe_err = ret);
+
+ out2:
+ kfree(pl080.chanllis);
out:
amba_release_regions(dev);
- return ret;
+ return (probe_err = ret);
}
static struct amba_id pl080_ids[] = {
@@ -309,26 +319,32 @@ static struct amba_driver pl080_driver =
int pl080_init_dma(dma_t * dma_chan, struct dma_ops * ops){
int i;
+ int retval = 0;
- for(i = 0; i < MAX_DMA_CHANNELS; i++){
- dma_chan[i].dma_base = (unsigned int)pl080.base;
- }
- ops->request = pl080_request;
- ops->free = pl080_free;
- ops->enable = pl080_enable ;
- ops->disable = pl080_disable;
- ops->residue = pl080_residue;
- ops->setspeed = pl080_setspeed;
- ops->type = pl080_type;
+ if(ops){
+
+ for(i = 0; i < MAX_DMA_CHANNELS; i++){
+ dma_chan[i].dma_base = (unsigned int)pl080.base;
+ }
+ ops->request = pl080_request;
+ ops->free = pl080_free;
+ ops->enable = pl080_enable ;
+ ops->disable = pl080_disable;
+ ops->residue = pl080_residue;
+ ops->setspeed = pl080_setspeed;
+ ops->type = pl080_type;
- /* PL080 specific */
- ops->extra_ops = &pl080_ops;
+ /* PL080 specific */
+ ops->extra_ops = &pl080_ops;
- pl080_driver.dmac_ops = ops;
+ pl080_driver.dmac_ops = ops;
- amba_init_dma(dma_chan);
+ retval = amba_init_dma(dma_chan);
+ } else {
+ printk(KERN_ERR "pl080_init_dma() board has not supplied
operations\n");
+ }
- return 0;
+ return retval;
}
/*
@@ -355,14 +371,20 @@ static int __devexit pl080_remove(struct
/*
* Module initialization
+ * - probe errors are ignored by driver registration
+ * - force the initialization to fail if the probe fails
*/
static int __init pl080_init(void)
{
pl080.base = NULL;
pl080.chanllis = NULL; /* LLI details for each DMA channel */
pl080.pool = NULL;
-
- return amba_driver_register(&pl080_driver);
+
+ probe_err = 0;
+
+ amba_driver_register(&pl080_driver);
+
+ return probe_err;
}
/*
* Module destruction
diff -purN arm_amba_pl080/include/linux/amba/dma.h
arm_amba_pl080err/include/linux/amba/dma.h
--- arm_amba_pl080/include/linux/amba/dma.h 2006-10-17
17:14:06.000000000 +0100
+++ arm_amba_pl080err/include/linux/amba/dma.h 2006-10-18
08:24:03.000000000 +0100
@@ -26,7 +26,7 @@ struct amba_dma_data {
};
extern dma_t * amba_get_chans (void);
-extern void amba_init_dma (dma_t *channels);
+extern int amba_init_dma (dma_t *channels);
struct amba_device * amba_get_device_with_name(char * name);
void amba_set_ops (struct dma_ops * ops);
-
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