From fae92216da87d1c78aa51c4503acb312a47266e9 Mon Sep 17 00:00:00 2001 From: Inaky Perez-Gonzalez Date: Fri, 23 Oct 2009 17:48:36 -0700 Subject: [PATCH] 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: Inaky Perez-Gonzalez --- drivers/net/wimax/i2400m/i2400m-sdio.h | 8 ++++++++ drivers/net/wimax/i2400m/sdio.c | 13 ++++++++++++- 2 files changed, 20 insertions(+), 1 deletion(-) diff --git a/drivers/net/wimax/i2400m/i2400m-sdio.h b/drivers/net/wimax/i2400m/i2400m-sdio.h index fba482c..b9c4bed 100644 --- a/drivers/net/wimax/i2400m/i2400m-sdio.h +++ b/drivers/net/wimax/i2400m/i2400m-sdio.h @@ -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 */ diff --git a/drivers/net/wimax/i2400m/sdio.c b/drivers/net/wimax/i2400m/sdio.c index 079f900..e8ad85c 100644 --- a/drivers/net/wimax/i2400m/sdio.c +++ b/drivers/net/wimax/i2400m/sdio.c @@ -159,6 +159,10 @@ function_enabled: /* * 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); -- 2.7.4