On 16/06/19 11:48 PM, Angelo Dureghello wrote: > Some controller as the ColdFire eshdc may require an endianness > byte swap, because DMA read endianness is not configurable. I would prefer something more generic, like adding another callback for ->request_done() e.g. diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c index f56ae6f153d4..a63e528cb885 100644 --- a/drivers/mmc/host/sdhci.c +++ b/drivers/mmc/host/sdhci.c @@ -2729,7 +2729,10 @@ static bool sdhci_request_done(struct sdhci_host *host) spin_unlock_irqrestore(&host->lock, flags); - mmc_request_done(host->mmc, mrq); + if (host->ops->request_done) + host->ops->request_done(host, mrq); + else + mmc_request_done(host->mmc, mrq); return false; } Then you can use the ->request_done() callback to iterate over the data->sg and make byte-swaps as needed. > > Signed-off-by: Angelo Dureghello <angelo@xxxxxxxx> > --- > drivers/mmc/host/sdhci.c | 19 +++++++++++++++++++ > drivers/mmc/host/sdhci.h | 7 +++++++ > 2 files changed, 26 insertions(+) > > diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c > index 59acf8e3331e..f56ae6f153d4 100644 > --- a/drivers/mmc/host/sdhci.c > +++ b/drivers/mmc/host/sdhci.c > @@ -2600,6 +2600,18 @@ static const struct mmc_host_ops sdhci_ops = { > .card_busy = sdhci_card_busy, > }; > > +static void sdhci_be_to_le(char *buff, u32 length) > +{ > + int i, size = length >> 2; > + u32 *buffer = (u32 *)buff; > + u32 temp; > + > + for (i = 0; i < size; i++) { > + temp = *buffer; > + *buffer++ = __le32_to_cpu(temp); > + } > +} > + > /*****************************************************************************\ > * * > * Request done * > @@ -2655,6 +2667,13 @@ static bool sdhci_request_done(struct sdhci_host *host) > host->bounce_addr, > host->bounce_buffer_size, > DMA_FROM_DEVICE); > + > + if (host->quirks2 & > + SDHCI_QUIRK2_USE_32BIT_BE_DMA_SWAP) > + sdhci_be_to_le( > + host->bounce_buffer, > + length); > + > sg_copy_from_buffer(data->sg, > data->sg_len, > host->bounce_buffer, > diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h > index 199712e7adbb..be08ff1a8c6f 100644 > --- a/drivers/mmc/host/sdhci.h > +++ b/drivers/mmc/host/sdhci.h > @@ -482,6 +482,13 @@ struct sdhci_host { > */ > #define SDHCI_QUIRK2_USE_32BIT_BLK_CNT (1<<18) > > +/* > + * On some architectures, as ColdFire/m68k, native endianness is big endian, > + * and the dma buffer is filled in big endian order only (no other options). > + * So, a swap is needed for these specific cases. > + */ > +#define SDHCI_QUIRK2_USE_32BIT_BE_DMA_SWAP (1<<19) > + > int irq; /* Device IRQ */ > void __iomem *ioaddr; /* Mapped address */ > char *bounce_buffer; /* For packing SDMA reads/writes */ >