On 06-12-23, 17:32, liu kaiwei wrote: > On Fri, Nov 24, 2023 at 9:11 PM Vinod Koul <vkoul@xxxxxxxxxx> wrote: > > > > On 02-11-23, 20:16, Kaiwei Liu wrote: > > > From: "kaiwei.liu" <kaiwei.liu@xxxxxxxxxx> > > > > Typo is subject line > > > > > > > > In the probe of dma, it will allocate device memory and do some > > > initalization settings. All operations are only at the software > > > level and don't need the DMA hardware power on. It doesn't need > > > to resume the device and set the device active as well. here > > > delete unnecessary operation. > > > > Don't you need to read or write to the device? Without enable that wont > > work right? > > > > Yes, it doesn't need to read or write to the device in the probe of DMA. > We will enable the DMA when allocating the DMA channel. So you will probe even if device is not present! I think it makes sense to access device registers in probe! -- ~Vinod
