Since 1fb654fd97ff("mmc: sdio: add reset callback to bus operations"),
sdio cards can be power cycled using mmc_hw_reset.
The use mmc_remove_host/mmc_add_host is discouraged, because these are
internal functions to the mmc core and should only be used by mmc hosts
Signed-off-by: Andreas Fenkart <afenkart@xxxxxxxxx>
---
drivers/net/wireless/mwifiex/sdio.c | 51 ++++++++++++++++++++++++++-----------
drivers/net/wireless/mwifiex/sdio.h | 3 +++
2 files changed, 39 insertions(+), 15 deletions(-)
diff --git a/drivers/net/wireless/mwifiex/sdio.c b/drivers/net/wireless/mwifiex/sdio.c
index a0b121f..e4c35ee 100644
--- a/drivers/net/wireless/mwifiex/sdio.c
+++ b/drivers/net/wireless/mwifiex/sdio.c
@@ -91,6 +91,7 @@ mwifiex_sdio_probe(struct sdio_func *func, const struct sdio_device_id *id)
return -ENOMEM;
card->func = func;
+ card->device_id = id;
func->card->quirks |= MMC_QUIRK_BLKSZ_FOR_BYTE_MODE;
@@ -2107,26 +2108,46 @@ mwifiex_update_mp_end_port(struct mwifiex_adapter *adapter, u16 port)
port, card->mp_data_port_mask);
}
+static void mwifiex_recreate_adapter(struct sdio_mmc_card *card)
+{
+ struct sdio_func *func = card->func;
+ const struct sdio_device_id *device_id = card->device_id;
+
+ /* TODO mmc_hw_reset does not require destroying and re-probing the
+ * whole adapter. Hence there was no need to for this rube-goldberg
+ * design to reload the fw from an external workqueue. If we don't
+ * destroy the adapter we could reload the fw from
+ * mwifiex_main_work_queue directly.
+ * The real difficulty with fw reset is to restore all the user
+ * settings applied through ioctl. By destroying and recreating the
+ * adapter, we take the easy way out, since we rely on user space to
+ * restore them. We assume that user space will treat the new
+ * incarnation of the adapter(interfaces) as if they had been just
+ * discovered and initializes them from scratch.
+ */
+
+ mwifiex_sdio_remove(func);
+
+ /* power cycle the adapter */
+ sdio_claim_host(func);
+ mmc_hw_reset(func->card->host);
+ sdio_release_host(func);
+
+ mwifiex_sdio_probe(func, device_id);
+}
+
static struct mwifiex_adapter *save_adapter;
static void mwifiex_sdio_card_reset_work(struct mwifiex_adapter *adapter)
{
struct sdio_mmc_card *card = adapter->card;
- struct mmc_host *target = card->func->card->host;
-
- /* The actual reset operation must be run outside of driver thread.
- * This is because mmc_remove_host() will cause the device to be
- * instantly destroyed, and the driver then needs to end its thread,
- * leading to a deadlock.
- *
- * We run it in a totally independent workqueue.
- */
- mwifiex_dbg(adapter, WARN, "Resetting card...\n");
- mmc_remove_host(target);
- /* 200ms delay is based on experiment with sdhci controller */
- mdelay(200);
- target->rescan_entered = 0; /* rescan non-removable cards */
- mmc_add_host(target);
+ /* TODO card pointer is unprotected. If the adapter is removed
+ * physically, sdio core might trigger mwifiex_sdio_remove, before this
+ * workqueue is run, which will destroy the adapter struct. When this
+ * workqueue eventually exceutes it will dereference an invalid adapter
+ * pointer
+ */
+ mwifiex_recreate_adapter(card);
}
/* This function read/write firmware */
diff --git a/drivers/net/wireless/mwifiex/sdio.h b/drivers/net/wireless/mwifiex/sdio.h
index 6f645cf..c44da61 100644
--- a/drivers/net/wireless/mwifiex/sdio.h
+++ b/drivers/net/wireless/mwifiex/sdio.h
@@ -262,6 +262,9 @@ struct sdio_mmc_card {
struct mwifiex_sdio_mpa_tx mpa_tx;
struct mwifiex_sdio_mpa_rx mpa_rx;
+
+ /* needed for card reset */
+ const struct sdio_device_id *device_id;
};
struct mwifiex_sdio_device {
--
2.1.4
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