> > I was just referring to using "<at>" instead of "@". The provider
> > doesn't really matter :)
>
> Ah, ok. Yahoo makes it practically impossible to send well-formed
> patches from the web interface, but as long as it's not completely
> rejected for casual email, I prefer to keep the number of spam
> addresses to the minimum.
Okay, well, that is up to Chris.
> Almost. There is one statement in the spec ("At the end of transfer, the Host
> Controller may issue or may not issue DMA Interrupt"), which makes
> me wonder whether a host hontroller may issue a DMA Interrupt also at
> the end of a transfer which doesn't finish at the boundary.
Then we'll have a "useless" update. Won't hurt AFAICS, but might
surprise people examining the debug output.
> In sdhci.c or sdhci.c? I see SDHCI_MAKE_BLKSZ is used also in
> drivers/mmc/host/sdhci-esdhc-imx.c and drivers/mmc/host/sdhci-of-esdhc.c.
In those, I think it is okay to leave 0x07, because they always want to
clear all bits.
> I only compile tested this so far, so no proper patch yet, but what I would
> write based on the comments is something like this:
(Sidenote: Indentation is broken. Tabwidth is 8)
> --- a/drivers/mmc/host/sdhci.h
> +++ b/drivers/mmc/host/sdhci.h
> @@ -201,6 +201,9 @@
> #define SDHCI_MAX_DIV_SPEC_200 256
> #define SDHCI_MAX_DIV_SPEC_300 2046
>
> +#define SDHCI_DEFAULT_BOUNDARY_SIZE (512 * 1024)
> +#define SDHCI_DEFAULT_BOUNDARY_ARG (ilog2(SDHCI_DEFAULT_BOUNDARY_SIZE) - 12)
> +
> struct sdhci_ops {
> #ifdef CONFIG_MMC_SDHCI_IO_ACCESSORS
> u32 (*read_l)(struct sdhci_host *host, int reg);
>
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -808,7 +808,8 @@ static void sdhci_prepare_data(struct sdhci_host *host,
> struct mmc_data *data)
> sdhci_set_transfer_irqs(host);
>
> /* We do not handle DMA boundaries, so set it to max (512 KiB) */
> - sdhci_writew(host, SDHCI_MAKE_BLKSZ(7, data->blksz), SDHCI_BLOCK_SIZE);
> + sdhci_writew(host, SDHCI_MAKE_BLKSZ(SDHCI_DEFAULT_BOUNDARY_ARG,
> + data->blksz), SDHCI_BLOCK_SIZE);
> sdhci_writew(host, data->blocks, SDHCI_BLOCK_COUNT);
> }
>
> @@ -1545,9 +1546,20 @@ static void sdhci_data_irq(struct sdhci_host *host, u32
> intmask)
> * boundaries, but as we can't disable the feature
> * we need to at least restart the transfer.
> */
> - if (intmask & SDHCI_INT_DMA_END)
> - sdhci_writel(host, sdhci_readl(host, SDHCI_DMA_ADDRESS),
> - SDHCI_DMA_ADDRESS);
> + if (intmask & SDHCI_INT_DMA_END) {
> + u32 dmastart, dmanow;
> + dmastart = sg_dma_address(host->data->sg);
Consecutive transfers won't work (I know you know ;)).
> + dmanow = sdhci_readl(host, SDHCI_DMA_ADDRESS);
> + /*
> + * Force update to the next DMA block boundary.
> + */
> + dmanow = (dmastart &
> + ~(SDHCI_DEFAULT_BOUNDARY_SIZE - 1)) +
> + SDHCI_DEFAULT_BOUNDARY_SIZE;
> + DBG("%s: next DMA address after 0x%08x is 0x%08x\n",
> + mmc_hostname(host->mmc), dmastart, dmanow);
> + sdhci_writel(host, dmanow, SDHCI_DMA_ADDRESS);
> + }
Other than that, looks like the right direction to me.
--
Pengutronix e.K. | Wolfram Sang |
Industrial Linux Solutions | http://www.pengutronix.de/ |
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