From: Phillip Potter phil@philpotter.co.uk
[ Upstream commit 4df2a8b0ad634d98a67e540a4e18a60f943e7d9f ]
Place a comment in hidma_mgmt_init explaining why success must currently be assumed, due to the cleanup issue that would need to be considered were this module ever to be unloadable or were this platform_driver_register call ever to fail.
Acked-By: Vinod Koul vkoul@kernel.org Acked-By: Sinan Kaya okaya@kernel.org Signed-off-by: Phillip Potter phil@philpotter.co.uk Link: https://lore.kernel.org/r/20210503115736.2104747-52-gregkh@linuxfoundation.o... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/dma/qcom/hidma_mgmt.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+)
diff --git a/drivers/dma/qcom/hidma_mgmt.c b/drivers/dma/qcom/hidma_mgmt.c index d64edeb6771a..f9640e37b139 100644 --- a/drivers/dma/qcom/hidma_mgmt.c +++ b/drivers/dma/qcom/hidma_mgmt.c @@ -423,6 +423,20 @@ static int __init hidma_mgmt_init(void) hidma_mgmt_of_populate_channels(child); } #endif + /* + * We do not check for return value here, as it is assumed that + * platform_driver_register must not fail. The reason for this is that + * the (potential) hidma_mgmt_of_populate_channels calls above are not + * cleaned up if it does fail, and to do this work is quite + * complicated. In particular, various calls of of_address_to_resource, + * of_irq_to_resource, platform_device_register_full, of_dma_configure, + * and of_msi_configure which then call other functions and so on, must + * be cleaned up - this is not a trivial exercise. + * + * Currently, this module is not intended to be unloaded, and there is + * no module_exit function defined which does the needed cleanup. For + * this reason, we have to assume success here. + */ platform_driver_register(&hidma_mgmt_driver);
return 0;