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Commit fae92216 authored by Inaky Perez-Gonzalez's avatar Inaky Perez-Gonzalez
Browse files

wimax/i2400m: don't retry SDIO enable in probe() paths 



The iwmc3200 has a quirk where retrying SDIO enable during the probe()
path causes bad interactions with the TOP function controller that
causes a reset storm. The workaround is simply not to retry an SDIO
enable in said path (and still do in the reset / reinitialization
paths).

The driver does so by checking i2400ms->debugfs_dentry to see if it
has been initialized; if not, it is in the probe() path. Document said
fact in i2400ms->debugfs_entry.

Signed-off-by: default avatarInaky Perez-Gonzalez <inaky@linux.intel.com>
parent 02eb41ef

drivers/net/wimax/i2400m/i2400m-sdio.h

+8 −0
Original line number Diff line number Diff line
@@ -100,6 +100,14 @@ enum { 
 * @tx_workqueue: workqeueue used for data TX; we don't use the

 *     system's workqueue as that might cause deadlocks with code in

 *     the bus-generic driver.

 *

 * @debugfs_dentry: dentry for the SDIO specific debugfs files

 *

 *     Note this value is set to NULL upon destruction; this is

 *     because some routinges use it to determine if we are inside the

 *     probe() path or some other path. When debugfs is disabled,

 *     creation sets the dentry to '(void*) -ENODEV', which is valid

 *     for the test.

 */

struct i2400ms {

	struct i2400m i2400m;		/* FIRST! See doc */

drivers/net/wimax/i2400m/sdio.c

+12 −1
Original line number Diff line number Diff line
@@ -159,6 +159,10 @@ int i2400ms_enable_function(struct i2400ms *i2400ms, unsigned maxtries) 
/*

 * Setup minimal device communication infrastructure needed to at

 * least be able to update the firmware.

 *

 * Note the ugly trick: if we are in the probe path

 * (i2400ms->debugfs_dentry == NULL), we only retry function

 * enablement one, to avoid racing with the iwmc3200 top controller.

 */

static

int i2400ms_bus_setup(struct i2400m *i2400m)
@@ -168,6 +172,7 @@ int i2400ms_bus_setup(struct i2400m *i2400m) 
		container_of(i2400m, struct i2400ms, i2400m);

	struct device *dev = i2400m_dev(i2400m);

	struct sdio_func *func = i2400ms->func;

	int retries;



	sdio_claim_host(func);

	result = sdio_set_block_size(func, I2400MS_BLK_SIZE);
@@ -177,7 +182,11 @@ int i2400ms_bus_setup(struct i2400m *i2400m) 
		goto error_set_blk_size;

	}



	result = i2400ms_enable_function(i2400ms, 1);

	if (i2400ms->iwmc3200 && i2400ms->debugfs_dentry == NULL)

		retries = 0;

	else

		retries = 1;

	result = i2400ms_enable_function(i2400ms, retries);

	if (result < 0) {

		dev_err(dev, "Cannot enable SDIO function: %d\n", result);

		goto error_func_enable;
@@ -415,6 +424,7 @@ int i2400ms_debugfs_add(struct i2400ms *i2400ms) 


error:

	debugfs_remove_recursive(i2400ms->debugfs_dentry);

	i2400ms->debugfs_dentry = NULL;

	return result;

}
@@ -531,6 +541,7 @@ void i2400ms_remove(struct sdio_func *func) 


	d_fnstart(3, dev, "SDIO func %p\n", func);

	debugfs_remove_recursive(i2400ms->debugfs_dentry);

	i2400ms->debugfs_dentry = NULL;

	i2400m_release(i2400m);

	sdio_set_drvdata(func, NULL);

	free_netdev(net_dev);