rt2800: change initialization sequence to fix system freeze

commit f4e1a4d3ecbb9e42bdf8e7869ee8a4ebfa27fb20 upstream.

My commit

commit c630ccf1a127578421a928489d51e99c05037054
Author: Stanislaw Gruszka <stf_xl@wp.pl>
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@dexmalabs.com>
Bisected-by: Igor Gnatenko <i.gnatenko.brain@gmail.com>
Cc: stable@vger.kernel.org # 3.10+
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/net/wireless/rt2x00/rt2800lib.c b/drivers/net/wireless/rt2x00/rt2800lib.c
index 33bfb19..f281971 100644 (file)
--- a/drivers/net/wireless/rt2x00/rt2800lib.c
+++ b/drivers/net/wireless/rt2x00/rt2800lib.c
@@ -4048,10 +4048,6 @@ static int rt2800_init_bbp(struct rt2x00_dev *rt2x00dev)
        u8 reg_id;
        u8 value;
 
-       if (unlikely(rt2800_wait_bbp_rf_ready(rt2x00dev) ||
-                    rt2800_wait_bbp_ready(rt2x00dev)))
-               return -EACCES;
-
        if (rt2x00_rt(rt2x00dev, RT5592)) {
                rt2800_init_bbp_5592(rt2x00dev);
                return 0;
@@ -5192,20 +5188,23 @@ int rt2800_enable_radio(struct rt2x00_dev *rt2x00dev)
                     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_init_bbp(rt2x00dev)))
+       if (unlikely(rt2800_wait_bbp_ready(rt2x00dev)))
                return -EIO;
 
+       rt2800_init_bbp(rt2x00dev);
        rt2800_init_rfcsr(rt2x00dev);
 
        if (rt2x00_is_usb(rt2x00dev) &&