2023-07-26 12:24:10

by Wang Ming

Subject: [PATCH v2] mmc: host: Use dev_err_probe instead of dev_err

It is possible that dma_request_chan will return EPROBE_DEFER,
which means that host->dev is not ready yet. In this case,
dev_err(host->dev), there will be no output. This patch fixes the bug.

Signed-off-by: Wang Ming <[email protected]>
---
drivers/mmc/host/dw_mmc.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
index 829af2c98a44..5a3eefd86931 100644
--- a/drivers/mmc/host/dw_mmc.c
+++ b/drivers/mmc/host/dw_mmc.c
@@ -841,9 +841,9 @@ static int dw_mci_edmac_init(struct dw_mci *host)

host->dms->ch = dma_request_chan(host->dev, "rx-tx");
if (IS_ERR(host->dms->ch)) {
- int ret = PTR_ERR(host->dms->ch);
+ int ret = dev_err_probe(host->dev, PTR_ERR(host->dms->ch),
+ "Failed to get external DMA channel.\n");

- dev_err(host->dev, "Failed to get external DMA channel.\n");
kfree(host->dms);
host->dms = NULL;
return ret;
--
2.25.1

2023-08-07 16:16:22

by Ulf Hansson

Subject: Re: [PATCH v2] mmc: host: Use dev_err_probe instead of dev_err

On Wed, 26 Jul 2023 at 13:50, Wang Ming <[email protected]> wrote:
>
> It is possible that dma_request_chan will return EPROBE_DEFER,
> which means that host->dev is not ready yet. In this case,
> dev_err(host->dev), there will be no output. This patch fixes the bug.

More exactly, what do you mean by "host->dev is not ready yet"?

Did you really test this?

Kind regards
Uffe

>
> Signed-off-by: Wang Ming <[email protected]>
> ---
> drivers/mmc/host/dw_mmc.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
> index 829af2c98a44..5a3eefd86931 100644
> --- a/drivers/mmc/host/dw_mmc.c
> +++ b/drivers/mmc/host/dw_mmc.c
> @@ -841,9 +841,9 @@ static int dw_mci_edmac_init(struct dw_mci *host)
>
> host->dms->ch = dma_request_chan(host->dev, "rx-tx");
> if (IS_ERR(host->dms->ch)) {
> - int ret = PTR_ERR(host->dms->ch);
> + int ret = dev_err_probe(host->dev, PTR_ERR(host->dms->ch),
> + "Failed to get external DMA channel.\n");
>
> - dev_err(host->dev, "Failed to get external DMA channel.\n");
> kfree(host->dms);
> host->dms = NULL;
> return ret;
> --
> 2.25.1
>