Re: [PATCH 22/25] dmaengine: dw-edma: Replace chip ID number with device name

Manivannan Sadhasivam
2022-03-25T10:02:18Z

On Thu, Mar 24, 2022 at 04:48:33AM +0300, Serge Semin wrote:
> Using some abstract number as the DW eDMA chip identifier isn't really
> practical. First of all there can be more than one DW eDMA controller on
> the platform some of them can be detected as the PCIe end-points, some of
> them can be embedded into the DW PCIe Root Port/End-point controllers.
> Seeing some abstract number in for instance IRQ handlers list doesn't give
> a notion regarding their reference to the particular DMA controller.
> Secondly current DW eDMA chip id implementation doesn't provide the
> multi-eDMA platforms support for same reason of possibly having eDMA
> detected on different system buses. At the same time re-implementing
> something ida-based won't give much benefits especially seeing the DW eDMA
> chip ID is only used in the IRQ request procedure. So to speak in order to
> preserve the code simplicity and get to have the multi-eDMA platforms
> support let's just use the parental device name to create the DW eDMA
> controller name.
>
> Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
> ---
> drivers/dma/dw-edma/dw-edma-core.c | 3 ++-
> drivers/dma/dw-edma/dw-edma-core.h | 2 +-
> drivers/dma/dw-edma/dw-edma-pcie.c | 1 -
> include/linux/dma/edma.h | 1 -
> 4 files changed, 3 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/dma/dw-edma/dw-edma-core.c b/drivers/dma/dw-edma/dw-edma-core.c
> index dbe1119fd1d2..72a51970bfba 100644
> --- a/drivers/dma/dw-edma/dw-edma-core.c
> +++ b/drivers/dma/dw-edma/dw-edma-core.c
> @@ -970,7 +970,8 @@ int dw_edma_probe(struct dw_edma_chip *chip)
> if (!dw->chan)
> return -ENOMEM;
>
> - snprintf(dw->name, sizeof(dw->name), "dw-edma-core:%d", chip->id);
> + snprintf(dw->name, sizeof(dw->name), "dw-edma-core:%s",
> + dev_name(chip->dev));
>
> /* Disable eDMA, only to establish the ideal initial conditions */
> dw_edma_v0_core_off(dw);
> diff --git a/drivers/dma/dw-edma/dw-edma-core.h b/drivers/dma/dw-edma/dw-edma-core.h
> index 980adb079182..dc25798d4ba9 100644
> --- a/drivers/dma/dw-edma/dw-edma-core.h
> +++ b/drivers/dma/dw-edma/dw-edma-core.h
> @@ -96,7 +96,7 @@ struct dw_edma_irq {
> };
>
> struct dw_edma {
> - char name[20];
> + char name[30];

I'm not sure if this length is sufficient. Other than this,

Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

Thanks,
Mani

>
> struct dma_device dma;
>
> diff --git a/drivers/dma/dw-edma/dw-edma-pcie.c b/drivers/dma/dw-edma/dw-edma-pcie.c
> index f530bacfd716..3f9dadc73854 100644
> --- a/drivers/dma/dw-edma/dw-edma-pcie.c
> +++ b/drivers/dma/dw-edma/dw-edma-pcie.c
> @@ -222,7 +222,6 @@ static int dw_edma_pcie_probe(struct pci_dev *pdev,
>
> /* Data structure initialization */
> chip->dev = dev;
> - chip->id = pdev->devfn;
>
> chip->mf = vsec_data.mf;
> chip->nr_irqs = nr_irqs;
> diff --git a/include/linux/dma/edma.h b/include/linux/dma/edma.h
> index 5cc87cfdd685..241c5a97ddf4 100644
> --- a/include/linux/dma/edma.h
> +++ b/include/linux/dma/edma.h
> @@ -73,7 +73,6 @@ enum dw_edma_map_format {
> */
> struct dw_edma_chip {
> struct device *dev;
> - int id;
> int nr_irqs;
> const struct dw_edma_core_ops *ops;
> u32 flags;
> --
> 2.35.1
>