On Tue, Feb 20, 2018 at 2:30 PM, Eugeniy Paltsev
<Eugeniy.Paltsev at synopsys.com> wrote:
> This patch adds support for the DW AXI DMAC controller.
> DW AXI DMAC is a part of HSDK development board from Synopsys.
>
> In this driver implementation only DMA_MEMCPY transfers are
> supported.
Just few comments, code looks fine I hope.
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -13344,6 +13344,12 @@ F: include/linux/dma/dw.h
> F: include/linux/platform_data/dma-dw.h
> F: drivers/dma/dw/
>
> +SYNOPSYS DESIGNWARE AXI DMAC DRIVER
> +M: Eugeniy Paltsev <Eugeniy.Paltsev at synopsys.com>
> +S: Maintained
> +F: drivers/dma/dwi-axi-dmac/
> +F: Documentation/devicetree/bindings/dma/snps,dw-axi-dmac.txt
AXI is earlier in alphabet than DMAC in previous record.
Linus even submitted a script last year to sort the MAINTAINERS data base.
> +/*
> + * Synopsys DesignWare AXI DMA Controller driver.
> + *
> + * Copyright (C) 2017-2018 Synopsys, Inc. (www.synopsys.com)
> + * Author: Eugeniy Paltsev <Eugeniy.Paltsev at synopsys.com>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + *
> + */
Now we have SPDX identifiers.
> +static u32 axi_chan_get_xfer_width(struct axi_dma_chan *chan, dma_addr_t src,
> + dma_addr_t dst, size_t len)
> +{
> + u32 max_width = chan->chip->dw->hdata->m_data_width;
> +
> + return min_t(size_t, __ffs(src | dst | len), max_width);
size_t -> u32 ?
> +}
> + unsigned int timeout = 20; /* timeout iterations */
> + do {
> + if (axi_chan_irq_read(chan) & DWAXIDMAC_IRQ_SUSPENDED) {
> + ret = 0;
> + break;
> + }
> + udelay(2);
> + } while (timeout--);
Off-by-one. You will have 21 tries here.
} while (--timeout);
--
With Best Regards,
Andy Shevchenko
