| Message ID | 20190326152139.18609-3-thirtythreeforty@gmail.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | staging: mt7621-mmc: correctness fixes | expand |
On Tue, Mar 26, 2019 at 09:21:39AM -0600, George Hilliard wrote: > 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@gmail.com> > --- > v2: rewrite of v1 > v3: Remove BUG_ON() calls > v4: Indent style fixup > > 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 e346167754bd..ed63bd3ba6cc 100644 > --- a/drivers/staging/mt7621-mmc/sd.c > +++ b/drivers/staging/mt7621-mmc/sd.c > @@ -466,7 +466,11 @@ 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)) Did you run your patch through checkpatch.pl? It should have reported an error here :(
On Tue, Mar 26, 2019 at 6:46 PM Greg Kroah-Hartman <gregkh@linuxfoundation.org> wrote: > > On Tue, Mar 26, 2019 at 09:21:39AM -0600, George Hilliard wrote: > > - 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)) > > Did you run your patch through checkpatch.pl? It should have reported > an error here :( No, I didn't. My mistake, sorry. Will fix up and resend again. George
diff --git a/drivers/staging/mt7621-mmc/sd.c b/drivers/staging/mt7621-mmc/sd.c index e346167754bd..ed63bd3ba6cc 100644 --- a/drivers/staging/mt7621-mmc/sd.c +++ b/drivers/staging/mt7621-mmc/sd.c @@ -466,7 +466,11 @@ 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); @@ -488,7 +492,6 @@ 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); @@ -670,7 +673,13 @@ 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) @@ -696,7 +705,6 @@ 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); @@ -1687,6 +1695,8 @@ 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);
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@gmail.com> --- v2: rewrite of v1 v3: Remove BUG_ON() calls v4: Indent style fixup drivers/staging/mt7621-mmc/sd.c | 18 ++++++++++++++---- 1 file changed, 14 insertions(+), 4 deletions(-)