The module was initializing completions whenever it was going to wait on them, and not when the completion was allocated. This is incorrect according to the completion docs: Calling init_completion() on the same completion object twice is most likely a bug [...] Re-initialization is also unnecessary because the module never uses complete_all(). Fix this by only ever initializing the completion a single time. Signed-off-by: George Hilliard <thirtythreeforty@xxxxxxxxx> --- drivers/staging/mt7621-mmc/sd.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/drivers/staging/mt7621-mmc/sd.c b/drivers/staging/mt7621-mmc/sd.c index 89fbc0a1dec7..c272aa780719 100644 --- a/drivers/staging/mt7621-mmc/sd.c +++ b/drivers/staging/mt7621-mmc/sd.c @@ -467,7 +467,9 @@ static unsigned int msdc_command_start(struct msdc_host *host, host->cmd = cmd; host->cmd_rsp = resp; - init_completion(&host->cmd_done); + // The completion should have been consumed by the previous command + // response handler, because the mmc requests should be serialized + BUG_ON(completion_done(&host->cmd_done)); sdr_set_bits(host->base + MSDC_INTEN, wints); sdc_send_cmd(rawcmd, cmd->arg); @@ -489,7 +491,6 @@ static unsigned int msdc_command_resp(struct msdc_host *host, MSDC_INT_ACMD19_DONE; BUG_ON(in_interrupt()); - //init_completion(&host->cmd_done); //sdr_set_bits(host->base + MSDC_INTEN, wints); spin_unlock(&host->lock); @@ -673,7 +674,10 @@ static int msdc_do_request(struct mmc_host *mmc, struct mmc_request *mrq) //msdc_clr_fifo(host); /* no need */ msdc_dma_on(); /* enable DMA mode first!! */ - init_completion(&host->xfer_done); + + // The completion should have been consumed by the previous xfer + // response handler, because the mmc requests should be serialized + BUG_ON(completion_done(&host->xfer_done)); /* start the command first*/ if (msdc_command_start(host, cmd, CMD_TIMEOUT) != 0) @@ -692,7 +696,6 @@ static int msdc_do_request(struct mmc_host *mmc, struct mmc_request *mrq) /* for read, the data coming too fast, then CRC error * start DMA no business with CRC. */ - //init_completion(&host->xfer_done); msdc_dma_start(host); spin_unlock(&host->lock); @@ -1684,6 +1687,8 @@ static int msdc_drv_probe(struct platform_device *pdev) } msdc_init_gpd_bd(host, &host->dma); + init_completion(&host->cmd_done); + init_completion(&host->xfer_done); INIT_DELAYED_WORK(&host->card_delaywork, msdc_tasklet_card); spin_lock_init(&host->lock); msdc_init_hw(host); -- 2.21.0