On Mon, Apr 18, 2022 at 04:48:33PM +0300, Serge Semin wrote: > On Fri, Mar 25, 2022 at 11:45:03PM +0530, Manivannan Sadhasivam wrote: > > On Thu, Mar 24, 2022 at 04:48:35AM +0300, Serge Semin wrote: > > > DW eDMA driver private data is preserved in the passed DW eDMA chip info > > > structure. If either probe procedure failed or for some reason the passed > > > info object doesn't have private data pointer initialized we need to halt > > > the DMA device cleanup procedure in order to prevent possible system > > > crashes. > > > > > > > > How come remove() could happen when probe() failed? If you hit this issue then > > something else is utterly going wrong. > > It fully depends on the DW eDMA client driver implementation, which > can't and in general shouldn't be guessed. But what must be done in > the DW eDMA driver is a protection against the invalid data being > passed to the exported API methods. That wrong situation must be > detected and handled in the API user code. It's much easier to do by > having an error code returned from the dw_edma_remove() method than > catching random system crashes. > Even though I don't see any practical issue, I'm fine with this. Thanks, Mani > -Sergey > > > > > Thanks, > > Mani > > > > > Signed-off-by: Serge Semin <Sergey.Semin@xxxxxxxxxxxxxxxxxxxx> > > > --- > > > drivers/dma/dw-edma/dw-edma-core.c | 4 ++++ > > > 1 file changed, 4 insertions(+) > > > > > > diff --git a/drivers/dma/dw-edma/dw-edma-core.c b/drivers/dma/dw-edma/dw-edma-core.c > > > index ca5cd7c99571..b932682a8ba8 100644 > > > --- a/drivers/dma/dw-edma/dw-edma-core.c > > > +++ b/drivers/dma/dw-edma/dw-edma-core.c > > > @@ -1030,6 +1030,10 @@ int dw_edma_remove(struct dw_edma_chip *chip) > > > struct dw_edma *dw = chip->dw; > > > int i; > > > > > > + /* Skip removal if no private data found */ > > > + if (!dw) > > > + return -ENODEV; > > > + > > > /* Disable eDMA */ > > > dw_edma_v0_core_off(dw); > > > > > > -- > > > 2.35.1 > > >
