On Fri, Mar 25, 2022 at 11:33:57AM +0530, Manivannan Sadhasivam wrote: > On Thu, Mar 24, 2022 at 04:48:26AM +0300, Serge Semin wrote: > > Currently all the DW eDMA DebugFS nodes descriptors are allocated on > > stack, while the DW eDMA driver private data and CSR limits are statically > > preserved. Such design won't work for the multi-eDMA platforms. > > Can you please explain why? > > > As a > > preparation to adding the multi-eDMA system setups support we need to have > > each DebugFS node separately allocated and described. Afterwards we'll put > > an addition info there like Read/Write channel flag, channel ID, DW eDMA > > private data reference. > > > > Note this conversion is mainly required due to having the legacy DW eDMA > > controllers with indirect Read/Write channels context CSRs access. If we > > didn't need to have a synchronized access to these registers the DebugFS > > code of the driver would have been much simpler. > > > > I fail to understand how this change is beneficial or the exact issue. > I think I get the reasoning after going through the successive patches. Thanks, Mani > > Signed-off-by: Serge Semin <Sergey.Semin@xxxxxxxxxxxxxxxxxxxx> > > --- > > drivers/dma/dw-edma/dw-edma-v0-debugfs.c | 15 ++++++++++++--- > > 1 file changed, 12 insertions(+), 3 deletions(-) > > > > diff --git a/drivers/dma/dw-edma/dw-edma-v0-debugfs.c b/drivers/dma/dw-edma/dw-edma-v0-debugfs.c > > index afd519d9568b..7eb0147912fa 100644 > > --- a/drivers/dma/dw-edma/dw-edma-v0-debugfs.c > > +++ b/drivers/dma/dw-edma/dw-edma-v0-debugfs.c > > @@ -53,7 +53,8 @@ struct dw_edma_debugfs_entry { > > > > static int dw_edma_debugfs_u32_get(void *data, u64 *val) > > { > > - void __iomem *reg = data; > > + struct dw_edma_debugfs_entry __iomem *entry = data; > > Why the entry has to be of __iomem? > > Thanks, > Mani > > > + void __iomem *reg = entry->reg; > > > > if (dw->chip->mf == EDMA_MF_EDMA_LEGACY && > > reg >= (void __iomem *)®s->type.legacy.ch) { > > @@ -94,14 +95,22 @@ static int dw_edma_debugfs_u32_get(void *data, u64 *val) > > } > > DEFINE_DEBUGFS_ATTRIBUTE(fops_x32, dw_edma_debugfs_u32_get, NULL, "0x%08llx\n"); > > > > -static void dw_edma_debugfs_create_x32(const struct dw_edma_debugfs_entry entries[], > > +static void dw_edma_debugfs_create_x32(const struct dw_edma_debugfs_entry ini[], > > int nr_entries, struct dentry *dir) > > { > > + struct dw_edma_debugfs_entry *entries; > > int i; > > > > + entries = devm_kcalloc(dw->chip->dev, nr_entries, sizeof(*entries), > > + GFP_KERNEL); > > + if (!entries) > > + return; > > + > > for (i = 0; i < nr_entries; i++) { > > + entries[i] = ini[i]; > > + > > debugfs_create_file_unsafe(entries[i].name, 0444, dir, > > - entries[i].reg, &fops_x32); > > + &entries[i], &fops_x32); > > } > > } > > > > -- > > 2.35.1 > >