The following panic is captured in ker3.14, but the issue still exists
in latest kernel.
---------------------------------------------------------------------
[ 20.738217] c0 3136 (Compiler) Unable to handle kernel NULL pointer dereference
at virtual address 00000578
......
[ 20.738499] c0 3136 (Compiler) PC is at _raw_spin_lock_irqsave+0x24/0x60
[ 20.738527] c0 3136 (Compiler) LR is at _raw_spin_lock_irqsave+0x20/0x60
[ 20.740134] c0 3136 (Compiler) Call trace:
[ 20.740165] c0 3136 (Compiler) [<ffffffc0008ee900>] _raw_spin_lock_irqsave+0x24/0x60
[ 20.740200] c0 3136 (Compiler) [<ffffffc0000dd024>] __wake_up+0x1c/0x54
[ 20.740230] c0 3136 (Compiler) [<ffffffc000639414>] mmc_wait_data_done+0x28/0x34
[ 20.740262] c0 3136 (Compiler) [<ffffffc0006391a0>] mmc_request_done+0xa4/0x220
[ 20.740314] c0 3136 (Compiler) [<ffffffc000656894>] sdhci_tasklet_finish+0xac/0x264
[ 20.740352] c0 3136 (Compiler) [<ffffffc0000a2b58>] tasklet_action+0xa0/0x158
[ 20.740382] c0 3136 (Compiler) [<ffffffc0000a2078>] __do_softirq+0x10c/0x2e4
[ 20.740411] c0 3136 (Compiler) [<ffffffc0000a24bc>] irq_exit+0x8c/0xc0
[ 20.740439] c0 3136 (Compiler) [<ffffffc00008489c>] handle_IRQ+0x48/0xac
[ 20.740469] c0 3136 (Compiler) [<ffffffc000081428>] gic_handle_irq+0x38/0x7c
----------------------------------------------------------------------
Because in SMP, "mrq" has race condition between below two paths:
path1: CPU0: <tasklet context>
static void mmc_wait_data_done(struct mmc_request *mrq)
{
mrq->host->context_info.is_done_rcv = true;
//
// If CPU0 has just finished "is_done_rcv = true" in path1, and at
// this moment, IRQ or ICache line missing happens in CPU0.
// What happens in CPU1 (path2)?
//
// If the mmcqd thread in CPU1(path2) hasn't entered to sleep mode:
// path2 would have chance to break from wait_event_interruptible
// in mmc_wait_for_data_req_done and continue to run for next
// mmc_request (mmc_blk_rw_rq_prep).
//
// Within mmc_blk_rq_prep, mrq is cleared to 0.
// If below line still gets host from "mrq" as the result of
// compiler, the panic happens as we traced.
wake_up_interruptible(&mrq->host->context_info.wait);
}
path2: CPU1: <The mmcqd thread runs mmc_queue_thread>
static int mmc_wait_for_data_req_done(...
{
...
while (1) {
wait_event_interruptible(context_info->wait,
(context_info->is_done_rcv ||
context_info->is_new_req));
static void mmc_blk_rw_rq_prep(...
{
...
memset(brq, 0, sizeof(struct mmc_blk_request));
This issue happens very coincidentally; however adding mdelay(1) in
mmc_wait_data_done as below could duplicate it easily.
static void mmc_wait_data_done(struct mmc_request *mrq)
{
mrq->host->context_info.is_done_rcv = true;
mdelay(1);
wake_up_interruptible(&mrq->host->context_info.wait);
}
At runtime, IRQ or ICache line missing may just happen at the same place
of the mdelay(1).
This patch gets the mmc_context_info at the beginning of function, it can
avoid this race condition.
Signed-off-by: Jialing Fu <jlfu@marvell.com>
Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: lintao <lintao@rock-chips.com>
test:Passed the special test.Test machine 15 for P9 and test 12H.
Have the test report form Quality department.
Signed-off-by: zhangqing <zhangqing@rock-chips.com>
before calling switch_set_state() when HDMI is removed.
For android hwcompser need to make sure vop is disabled when
received hdmi removing event.
Signed-off-by: Zheng Yang <zhengyang@rock-chips.com>
1.Cancel usb vbus detect work in driver shutdown rountine
2.Check empty list
3.Disable usb interrupt before usb mode change
TEST:
1.reboot test
2.while true; do
echo 1 > force_usb_mode;busybox sleep 5;
echo 2 > force_usb_mode;busybox sleep 5;
done
Signed-off-by: lyz <lyz@rock-chips.com>
For system can not be wakeup under following case:
step1. Disable HDMI.
step2. set system to deep sleep mode.
step3. remove HDMI connection.
step4. wake up system.
Signed-off-by: Zheng Yang <zhengyang@rock-chips.com>
1. To get logic address more stable, we ping 3 times to each
logic address. If the result is NACK for two times, this
logic address is not occupied.
2. If transmmit cec data failed, retry immediately.
4. set CECOP_IMAGE_VIEW_ON only taget to TV, not broadcasting.
Signed-off-by: Zheng Yang <zhengyang@rock-chips.com>
