[PATCH 5.0 268/346] staging: mt7621-mmc: Initialize completions a single time during probe

From: Greg Kroah-Hartman
Date: Thu May 30 2019 - 00:24:33 EST


[ Upstream commit 7ca8c2c8bbeda2a2a2a9898cd35066bc1dc83836 ]

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, and log if the completions are not consumed as intended
(this is not a fatal problem, but should not go unnoticed).

Signed-off-by: George Hilliard <thirtythreeforty@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/staging/mt7621-mmc/sd.c | 18 ++++++++++++++----
1 file changed, 14 insertions(+), 4 deletions(-)

diff --git a/drivers/staging/mt7621-mmc/sd.c b/drivers/staging/mt7621-mmc/sd.c
index 4b26ec896a96f..74f0e57ad2f15 100644
--- a/drivers/staging/mt7621-mmc/sd.c
+++ b/drivers/staging/mt7621-mmc/sd.c
@@ -468,7 +468,11 @@ 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
+ if (completion_done(&host->cmd_done))
+ dev_err(mmc_dev(host->mmc),
+ "previous command was not handled\n");

sdr_set_bits(host->base + MSDC_INTEN, wints);
sdc_send_cmd(rawcmd, cmd->arg);
@@ -490,7 +494,6 @@ 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);
@@ -674,7 +677,13 @@ 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
+ if (completion_done(&host->cmd_done))
+ dev_err(mmc_dev(host->mmc),
+ "previous transfer was not handled\n");

/* start the command first*/
if (msdc_command_start(host, cmd, CMD_TIMEOUT) != 0)
@@ -693,7 +702,6 @@ 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);
@@ -1688,6 +1696,8 @@ 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);
--
2.20.1