| Message ID | 20240928094454.3592-2-wsa+renesas@sang-engineering.com (mailing list archive) |
|---|---|
| State | Accepted |
| Delegated to: | Geert Uytterhoeven |
| Headers | show |
| Series | mmc: sh_mmcif: correctly report success when obtaining DMA channels | expand |
Hi Wolfram, On Sat, Sep 28, 2024 at 11:45 AM Wolfram Sang <wsa+renesas@sang-engineering.com> wrote: > The debug message could still report success when getting the channels > was OK but configuring them failed. This actually caused a minor detour > when debugging DMA problems, so make sure the success is only reported > when the channels are really ready-to-use. > > Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Thanks for your patch! > --- a/drivers/mmc/host/sh_mmcif.c > +++ b/drivers/mmc/host/sh_mmcif.c > @@ -439,14 +439,15 @@ static void sh_mmcif_request_dma(struct sh_mmcif_host *host) > if (IS_ERR(host->chan_rx)) > host->chan_rx = NULL; > } > - dev_dbg(dev, "%s: got channel TX %p RX %p\n", __func__, host->chan_tx, > - host->chan_rx); This was not a real success indicator, which could indeed confuse people, but an obfuscated NULL-pointer still prints as NULL, right? > if (!host->chan_tx || !host->chan_rx || > sh_mmcif_dma_slave_config(host, host->chan_tx, DMA_MEM_TO_DEV) || > sh_mmcif_dma_slave_config(host, host->chan_rx, DMA_DEV_TO_MEM)) > goto error; > > + dev_dbg(dev, "%s: got channel TX %p RX %p\n", __func__, host->chan_tx, > + host->chan_rx); This means we no longer see a debug message in case only one DMA channel could be requested, thus requiring manual addition of more code to find out what was really wrong? > + > return; > > error: Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
> > - dev_dbg(dev, "%s: got channel TX %p RX %p\n", __func__, host->chan_tx, > > - host->chan_rx); > > This was not a real success indicator, which could indeed confuse > people, but an obfuscated NULL-pointer still prints as NULL, right? Well... > > > if (!host->chan_tx || !host->chan_rx || > > sh_mmcif_dma_slave_config(host, host->chan_tx, DMA_MEM_TO_DEV) || > > sh_mmcif_dma_slave_config(host, host->chan_rx, DMA_DEV_TO_MEM)) > > goto error; > > > > + dev_dbg(dev, "%s: got channel TX %p RX %p\n", __func__, host->chan_tx, > > + host->chan_rx); > > This means we no longer see a debug message in case only one DMA > channel could be requested, thus requiring manual addition of more code > to find out what was really wrong? ... you can simply enable basic DMA debugging to find this out. I don't see value in adding a separate debug printout in the driver.
On Sat, 28 Sept 2024 at 11:44, Wolfram Sang <wsa+renesas@sang-engineering.com> wrote: > > The debug message could still report success when getting the channels > was OK but configuring them failed. This actually caused a minor detour > when debugging DMA problems, so make sure the success is only reported > when the channels are really ready-to-use. > > Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Applied for next, thanks! Kind regards Uffe > --- > drivers/mmc/host/sh_mmcif.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/drivers/mmc/host/sh_mmcif.c b/drivers/mmc/host/sh_mmcif.c > index 08b4312af94e..0e7fa3e9c9fe 100644 > --- a/drivers/mmc/host/sh_mmcif.c > +++ b/drivers/mmc/host/sh_mmcif.c > @@ -439,14 +439,15 @@ static void sh_mmcif_request_dma(struct sh_mmcif_host *host) > if (IS_ERR(host->chan_rx)) > host->chan_rx = NULL; > } > - dev_dbg(dev, "%s: got channel TX %p RX %p\n", __func__, host->chan_tx, > - host->chan_rx); > > if (!host->chan_tx || !host->chan_rx || > sh_mmcif_dma_slave_config(host, host->chan_tx, DMA_MEM_TO_DEV) || > sh_mmcif_dma_slave_config(host, host->chan_rx, DMA_DEV_TO_MEM)) > goto error; > > + dev_dbg(dev, "%s: got channel TX %p RX %p\n", __func__, host->chan_tx, > + host->chan_rx); > + > return; > > error: > -- > 2.45.2 >
diff --git a/drivers/mmc/host/sh_mmcif.c b/drivers/mmc/host/sh_mmcif.c index 08b4312af94e..0e7fa3e9c9fe 100644 --- a/drivers/mmc/host/sh_mmcif.c +++ b/drivers/mmc/host/sh_mmcif.c @@ -439,14 +439,15 @@ static void sh_mmcif_request_dma(struct sh_mmcif_host *host) if (IS_ERR(host->chan_rx)) host->chan_rx = NULL; } - dev_dbg(dev, "%s: got channel TX %p RX %p\n", __func__, host->chan_tx, - host->chan_rx); if (!host->chan_tx || !host->chan_rx || sh_mmcif_dma_slave_config(host, host->chan_tx, DMA_MEM_TO_DEV) || sh_mmcif_dma_slave_config(host, host->chan_rx, DMA_DEV_TO_MEM)) goto error; + dev_dbg(dev, "%s: got channel TX %p RX %p\n", __func__, host->chan_tx, + host->chan_rx); + return; error:
The debug message could still report success when getting the channels was OK but configuring them failed. This actually caused a minor detour when debugging DMA problems, so make sure the success is only reported when the channels are really ready-to-use. Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> --- drivers/mmc/host/sh_mmcif.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)