Hi Vinod,
On Thu, Jun 16, 2022 at 06:58:43AM -0700, Vinod Koul wrote:
On 14-06-22, 12:17, Dario Binacchi wrote:
Driver registration fails on SOC imx8mn as its supplier, the clock control module, is not ready. Since platform_driver_probe(), as reported by its description, is incompatible with deferred probing, we have to use platform_driver_register().
Fixes: a580b8c5429a ("dmaengine: mxs-dma: add dma support for i.MX23/28") Co-developed-by: Michael Trimarchi michael@amarulasolutions.com Signed-off-by: Michael Trimarchi michael@amarulasolutions.com Signed-off-by: Dario Binacchi dario.binacchi@amarulasolutions.com Cc: stable@vger.kernel.org
Changes in v3:
- Restore __init in front of mxs_dma_init() definition.
Changes in v2:
- Add the tag "Cc: stable@vger.kernel.org" in the sign-off area.
drivers/dma/mxs-dma.c | 9 +++------ 1 file changed, 3 insertions(+), 6 deletions(-)
diff --git a/drivers/dma/mxs-dma.c b/drivers/dma/mxs-dma.c index 994fc4d2aca4..6e90540fedc4 100644 --- a/drivers/dma/mxs-dma.c +++ b/drivers/dma/mxs-dma.c @@ -741,7 +741,7 @@ static struct dma_chan *mxs_dma_xlate(struct of_phandle_args *dma_spec, ofdma->of_node); } -static int __init mxs_dma_probe(struct platform_device *pdev) +static int mxs_dma_probe(struct platform_device *pdev)
why drop __init here, if there is a reason for that please split this change and document such reason...
The reason for dropping __init comes with this patch. With platform_driver_probe() the probe function is called only once, during init time. The problem with platform_driver_probe() is that the probe function will never be called again when it initially returns -EPROBE_DEFER. That's a problem for Dario: The clock is not yet available, the driver defers probe and will never be probed again when the clock is finally available.
With platform_driver_register() to which this patch switches to the probe function can be called at any time, thus __init has to be removed.
For what it's worth:
Acked-by: Sascha Hauer s.hauer@pengutronix.de
for this patch.
Sascha
{ struct device_node *np = pdev->dev.of_node; const struct mxs_dma_type *dma_type; @@ -839,10 +839,7 @@ static struct platform_driver mxs_dma_driver = { .name = "mxs-dma", .of_match_table = mxs_dma_dt_ids, },
- .probe = mxs_dma_probe,
}; -static int __init mxs_dma_module_init(void) -{
- return platform_driver_probe(&mxs_dma_driver, mxs_dma_probe);
-} -subsys_initcall(mxs_dma_module_init);
+module_platform_driver(mxs_dma_driver);
2.32.0
-- ~Vinod