Resend: [patch] hsi : Avoid race condition between HSI controller and HSI client when system restart and power down

[xtu4 <xiaobing.tu@intel.com>]

Avoid race condition between HSI controller and HSI client when system 
restart and power down

> hsi_isr_tasklet disabled in HSI_controller exit, but before HSI 
> controller exit,
> HSI client will cleanup, this cleanup will destroy the spinlock used 
> by the
> hsi_isr_tasklet,so if after HSI client cleanup, there still such 
> tasklet running,
> issue will happend. here is the issue stack as below.
> hsi-ctrl: WAKEf514b000: f9a800e5 00000010 60000006 00000000 013f5bf9 
> 582bf9b8 3d565244
> hsi-dlp: TTY device close request (mmgr, 133)
> hsi-dlp: port shutdown request
> mdm_ctrl: Unexpected RESET_OUT 0x0
> BUG: spinlock bad magic on CPU#3, zygote/137
> lock: f53a0fbc, .magic: 00000000, .owner: <none>/-1, .owner_cpu: 0
> Pid: 137, comm: zygote Tainted: G         C 3.0.34-141888-g9e0a6fb #1
> Call Trace:
>  [<c185c92c>] ? printk+0x1d/0x1f
>  [<c1860826>] spin_bug+0xa4/0xac
>  [<c14a5d6d>] do_raw_spin_lock+0x7d/0x170
>  [<c1866c86>] ? _raw_spin_unlock_irqrestore+0x26/0x50
>  [<c1866afc>] _raw_spin_lock_irqsave+0x2c/0x40
>  [<c12325d0>] complete+0x20/0x60
>  [<c1866c86>] ? _raw_spin_unlock_irqrestore+0x26/0x50
>  [<c1576ff9>] dlp_ctrl_complete_tx+0x29/0x40
>  [<c1570164>] hsi_isr_tasklet+0x394/0x11a0
>  [<c12709f5>] ? sched_clock_cpu+0xe5/0x150
>  [<c1251a39>] tasklet_hi_action+0x59/0x120
>  [<c12500d8>] ? it_real_fn+0x18/0xb0
>  [<c12522ab>] __do_softirq+0x9b/0x220
>  [<c1252210>] ? remote_softirq_receive+0x110/0x110
> Change-Id: I6a0ca0c14409bfc4cd7a2767a4f203c171ece007
> Signed-off-by: xiaobing tu <xiaobing.tu@intel.com>
> Signed-off-by: chao bi <chao.bi@intel.com>
> ---
>  drivers/hsi/clients/dlp_ctrl.c  |    4 ++++
>  drivers/hsi/clients/dlp_flash.c |    5 ++++-
>  drivers/hsi/clients/dlp_net.c   |    4 ++++
>  drivers/hsi/clients/dlp_trace.c |    1 -
>  drivers/hsi/clients/dlp_tty.c   |    5 ++++-
>  5 files changed, 16 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/hsi/clients/dlp_ctrl.c 
> b/drivers/hsi/clients/dlp_ctrl.c
> index b09f9e6..e980f0c 100644
> --- a/drivers/hsi/clients/dlp_ctrl.c
> +++ b/drivers/hsi/clients/dlp_ctrl.c
> @@ -394,6 +394,8 @@ static void dlp_ctrl_complete_tx(struct hsi_msg *msg)
>      struct dlp_command *dlp_cmd = msg->context;
>      struct dlp_channel *ch_ctx = dlp_cmd->channel;
>
> +    if (dlp_drv.channels[DLP_CHANNEL_CTRL] == NULL)
> +        return;
>      dlp_cmd->status = (msg->status == HSI_STATUS_COMPLETED) ? 0 : -EIO;
>
>      /* Command done, notify the sender */
> @@ -433,6 +435,8 @@ static void dlp_ctrl_complete_rx(struct hsi_msg *msg)
>      unsigned long flags;
>      int hsi_channel, elp_channel, ret, response, msg_complete, state;
>
> +    if (dlp_drv.channels[DLP_CHANNEL_CTRL] == NULL)
> +        return;
>      /* Copy the reponse */
>      memcpy(&params,
>             sg_virt(msg->sgt.sgl), sizeof(struct dlp_command_params));
> diff --git a/drivers/hsi/clients/dlp_flash.c 
> b/drivers/hsi/clients/dlp_flash.c
> index 885b73a..b333d74 100644
> --- a/drivers/hsi/clients/dlp_flash.c
> +++ b/drivers/hsi/clients/dlp_flash.c
> @@ -42,7 +42,6 @@
>   */
>  #define DLP_FLASH_NB_RX_MSG 10
>
> -
>  /*
>   * struct flashing_driver - HSI Modem flashing driver protocol
>   *
> @@ -259,6 +258,8 @@ static struct hsi_msg *dlp_boot_rx_dequeue(struct 
> dlp_channel *ch_ctx)
>  */
>  static void dlp_flash_complete_tx(struct hsi_msg *msg)
>  {
> +    if (dlp_drv.channels[DLP_CHANNEL_FLASH] == NULL)
> +        return;
>      /* Delete the received msg */
>      dlp_pdu_free(msg, -1);
>  }
> @@ -274,6 +275,8 @@ static void dlp_flash_complete_rx(struct hsi_msg 
> *msg)
>      struct dlp_flash_ctx *flash_ctx = ch_ctx->ch_data;
>      int ret;
>
> +    if (dlp_drv.channels[DLP_CHANNEL_FLASH] == NULL)
> +        return;
>      if (msg->status != HSI_STATUS_COMPLETED) {
>          pr_err(DRVNAME ": Invalid msg status: %d (ignored)\n",
>                  msg->status);
> diff --git a/drivers/hsi/clients/dlp_net.c 
> b/drivers/hsi/clients/dlp_net.c
> index f3ca817..0c3e672 100644
> --- a/drivers/hsi/clients/dlp_net.c
> +++ b/drivers/hsi/clients/dlp_net.c
> @@ -158,6 +158,8 @@ static void dlp_net_complete_tx(struct hsi_msg *pdu)
>      struct dlp_net_context *net_ctx = ch_ctx->ch_data;
>      struct dlp_xfer_ctx *xfer_ctx = &ch_ctx->tx;
>
> +    if (dlp_drv.channels[ch_ctx->hsi_channel] == NULL)
> +            return;
>      /* TX done, free the skb */
>      dev_kfree_skb(msg_param->skb);
>
> @@ -197,6 +199,8 @@ static void dlp_net_complete_rx(struct hsi_msg *pdu)
>      unsigned int *ptr;
>      unsigned long flags;
>
> +    if (dlp_drv.channels[ch_ctx->hsi_channel] == NULL)
> +        return;
>      /* Pop the CTRL queue */
>      write_lock_irqsave(&xfer_ctx->lock, flags);
>      dlp_hsi_controller_pop(xfer_ctx);
> diff --git a/drivers/hsi/clients/dlp_trace.c 
> b/drivers/hsi/clients/dlp_trace.c
> index fa91985..0067798 100644
> --- a/drivers/hsi/clients/dlp_trace.c
> +++ b/drivers/hsi/clients/dlp_trace.c
> @@ -84,7 +84,6 @@ static unsigned int log_dropped_data;
>  module_param_named(log_dropped_data, log_dropped_data, int, S_IRUGO | 
> S_IWUSR);
>  #endif
>
> -
>  /*
>   *
>   */
> diff --git a/drivers/hsi/clients/dlp_tty.c 
> b/drivers/hsi/clients/dlp_tty.c
> index 7774484..47f6697 100644
> --- a/drivers/hsi/clients/dlp_tty.c
> +++ b/drivers/hsi/clients/dlp_tty.c
> @@ -68,7 +68,6 @@ struct dlp_tty_context {
>      struct work_struct    do_tty_forward;
>  };
>
> -
>  /**
>   * Push as many RX PDUs  as possible to the controller FIFO
>   *
> @@ -337,6 +336,8 @@ static void dlp_tty_complete_tx(struct hsi_msg *pdu)
>      int wakeup, avail, pending;
>      unsigned long flags;
>
> +    if (dlp_drv.channels[DLP_CHANNEL_TTY] == NULL)
> +        return;
>      /* Recycle or Free the pdu */
>      write_lock_irqsave(&xfer_ctx->lock, flags);
>      dlp_pdu_delete(xfer_ctx, pdu);
> @@ -375,6 +376,8 @@ static void dlp_tty_complete_rx(struct hsi_msg *pdu)
>      unsigned long flags;
>      int ret;
>
> +    if (dlp_drv.channels[DLP_CHANNEL_TTY] == NULL)
> +        return;
>      /* Check the received PDU header & seq_num */
>      ret = dlp_pdu_header_check(xfer_ctx, pdu);
>      if (ret == -EINVAL) {