From 55466b60c3ea64f8dddd2d92b520f1a118258b4d Mon Sep 17 00:00:00 2001 From: Ioana Ciornei Date: Fri, 8 Jan 2021 11:07:24 +0200 Subject: [PATCH] bus: fsl-mc: return -EPROBE_DEFER when a device is not yet discovered The fsl_mc_get_endpoint() should return a pointer to the connected fsl_mc device, if there is one. By interrogating the MC firmware, we know if there is an endpoint or not so when the endpoint device is actually searched on the fsl-mc bus and not found we are hitting the case in which the device has not been yet discovered by the bus. Return -EPROBE_DEFER so that callers can differentiate this case. Signed-off-by: Ioana Ciornei Acked-by: Laurentiu Tudor Reviewed-by: Andrew Lunn Signed-off-by: Jakub Kicinski --- drivers/bus/fsl-mc/fsl-mc-bus.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/bus/fsl-mc/fsl-mc-bus.c b/drivers/bus/fsl-mc/fsl-mc-bus.c index 90e6846c4d10..fb0602fee1df 100644 --- a/drivers/bus/fsl-mc/fsl-mc-bus.c +++ b/drivers/bus/fsl-mc/fsl-mc-bus.c @@ -939,6 +939,15 @@ struct fsl_mc_device *fsl_mc_get_endpoint(struct fsl_mc_device *mc_dev) endpoint_desc.id = endpoint2.id; endpoint = fsl_mc_device_lookup(&endpoint_desc, mc_bus_dev); + /* + * We know that the device has an endpoint because we verified by + * interrogating the firmware. This is the case when the device was not + * yet discovered by the fsl-mc bus, thus the lookup returned NULL. + * Differentiate this case by returning EPROBE_DEFER. + */ + if (!endpoint) + return ERR_PTR(-EPROBE_DEFER); + return endpoint; } EXPORT_SYMBOL_GPL(fsl_mc_get_endpoint); -- 2.17.1