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authorStefan Richter <stefanr@s5r6.in-berlin.de>2009-06-16 19:15:25 +0200
committerStefan Richter <stefanr@s5r6.in-berlin.de>2009-06-16 22:48:09 +0200
commitd645f4dad056a98089df904294f66b96d04e91b6 (patch)
tree993ec9d0c64dac6fb4e1214f213220fbc0e29f63
parentfirewire: core: fix DMA unmapping in iso buffer removal (diff)
downloadlinux-d645f4dad056a98089df904294f66b96d04e91b6.tar.xz
linux-d645f4dad056a98089df904294f66b96d04e91b6.zip
firewire: core: fix iso context shutdown on card removal
If isochronous contexts existed when firewire-ohci was unloaded, the core iso shutdown functions crashed with NULL dereferences, and buffers etc. weren't released. How the fix works: We first copy the card driver's iso shutdown hooks into the dummy driver, then fw_destroy_nodes notifies upper layers of devices going away, these should shut down (including their iso contexts), wait_for_completion(&card->done) will be triggered after upper layers gave up all fw_device references, after which the card driver's shutdown proceeds. Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
-rw-r--r--drivers/firewire/core-card.c18
1 files changed, 11 insertions, 7 deletions
diff --git a/drivers/firewire/core-card.c b/drivers/firewire/core-card.c
index 667603ac14b1..543fccac81bb 100644
--- a/drivers/firewire/core-card.c
+++ b/drivers/firewire/core-card.c
@@ -461,11 +461,11 @@ EXPORT_SYMBOL(fw_card_add);
/*
- * The next few functions implements a dummy driver that use once a
- * card driver shuts down an fw_card. This allows the driver to
- * cleanly unload, as all IO to the card will be handled by the dummy
- * driver instead of calling into the (possibly) unloaded module. The
- * dummy driver just fails all IO.
+ * The next few functions implement a dummy driver that is used once a card
+ * driver shuts down an fw_card. This allows the driver to cleanly unload,
+ * as all IO to the card will be handled (and failed) by the dummy driver
+ * instead of calling into the module. Only functions for iso context
+ * shutdown still need to be provided by the card driver.
*/
static int dummy_enable(struct fw_card *card, u32 *config_rom, size_t length)
@@ -512,7 +512,7 @@ static int dummy_enable_phys_dma(struct fw_card *card,
return -ENODEV;
}
-static struct fw_card_driver dummy_driver = {
+static const struct fw_card_driver dummy_driver_template = {
.enable = dummy_enable,
.update_phy_reg = dummy_update_phy_reg,
.set_config_rom = dummy_set_config_rom,
@@ -531,6 +531,8 @@ void fw_card_release(struct kref *kref)
void fw_core_remove_card(struct fw_card *card)
{
+ struct fw_card_driver dummy_driver = dummy_driver_template;
+
card->driver->update_phy_reg(card, 4,
PHY_LINK_ACTIVE | PHY_CONTENDER, 0);
fw_core_initiate_bus_reset(card, 1);
@@ -539,7 +541,9 @@ void fw_core_remove_card(struct fw_card *card)
list_del_init(&card->link);
mutex_unlock(&card_mutex);
- /* Set up the dummy driver. */
+ /* Switch off most of the card driver interface. */
+ dummy_driver.free_iso_context = card->driver->free_iso_context;
+ dummy_driver.stop_iso = card->driver->stop_iso;
card->driver = &dummy_driver;
fw_destroy_nodes(card);