[ 06/71] rt2800: change initialization sequence to fix system freeze

From: Greg Kroah-Hartman
Date: Sun Sep 29 2013 - 15:38:40 EST


3.11-stable review patch. If anyone has any objections, please let me know.

------------------

From: Stanislaw Gruszka <sgruszka@xxxxxxxxxx>

commit f4e1a4d3ecbb9e42bdf8e7869ee8a4ebfa27fb20 upstream.

My commit

commit c630ccf1a127578421a928489d51e99c05037054
Author: Stanislaw Gruszka <stf_xl@xxxxx>
Date: Sat Mar 16 19:19:46 2013 +0100

rt2800: rearrange bbp/rfcsr initialization

make Maxim machine freeze when try to start wireless device.

Initialization order and sending MCU_BOOT_SIGNAL request, changed in
above commit, is important. Doing things incorrectly make PCIe bus
problems, which can froze the machine.

This patch change initialization sequence like vendor driver do:
function NICInitializeAsic() from
2011_1007_RT5390_RT5392_Linux_STA_V2.5.0.3_DPO (PCI devices) and
DPO_RT5572_LinuxSTA_2.6.1.3_20121022 (according Mediatek, latest driver
for RT8070/RT3070/RT3370/RT3572/RT5370/RT5372/RT5572 USB devices).
It fixes freezes on Maxim system.

Resolve:
https://bugzilla.redhat.com/show_bug.cgi?id=1000679

Reported-and-tested-by: Maxim Polyakov <polyakov@xxxxxxxxxxxxx>
Bisected-by: Igor Gnatenko <i.gnatenko.brain@xxxxxxxxx>
Signed-off-by: Stanislaw Gruszka <sgruszka@xxxxxxxxxx>
Signed-off-by: John W. Linville <linville@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/net/wireless/rt2x00/rt2800lib.c | 11 ++++++-----
1 file changed, 6 insertions(+), 5 deletions(-)

--- a/drivers/net/wireless/rt2x00/rt2800lib.c
+++ b/drivers/net/wireless/rt2x00/rt2800lib.c
@@ -5404,19 +5404,20 @@ int rt2800_enable_radio(struct rt2x00_de
rt2800_init_registers(rt2x00dev)))
return -EIO;

+ if (unlikely(rt2800_wait_bbp_rf_ready(rt2x00dev)))
+ return -EIO;
+
/*
* Send signal to firmware during boot time.
*/
rt2800_register_write(rt2x00dev, H2M_BBP_AGENT, 0);
rt2800_register_write(rt2x00dev, H2M_MAILBOX_CSR, 0);
- if (rt2x00_is_usb(rt2x00dev)) {
+ if (rt2x00_is_usb(rt2x00dev))
rt2800_register_write(rt2x00dev, H2M_INT_SRC, 0);
- rt2800_mcu_request(rt2x00dev, MCU_BOOT_SIGNAL, 0, 0, 0);
- }
+ rt2800_mcu_request(rt2x00dev, MCU_BOOT_SIGNAL, 0, 0, 0);
msleep(1);

- if (unlikely(rt2800_wait_bbp_rf_ready(rt2x00dev) ||
- rt2800_wait_bbp_ready(rt2x00dev)))
+ if (unlikely(rt2800_wait_bbp_ready(rt2x00dev)))
return -EIO;

rt2800_init_bbp(rt2x00dev);


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