Re: [PATCH v2 1/2] mmc: sdhci: add sdma_buffer_boundary_arg member to sdhci_host

From: Adrian Hunter
Date: Thu Aug 03 2017 - 07:46:04 EST


On 02/08/17 11:38, srinivas.kandagatla@xxxxxxxxxx wrote:
> From: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>
>
> This patch adds sdma_buffer_boundary_arg member to struct sdhci_host to
> give more flexibility to drivers to control the sdma boundary buffer value
> and also to fix issue on some sdhci controllers which are broken when
> HOST SDMA Buffer Boundary is programmed in Block Size Register (0x04)
> when using ADMA. Qualcomm sdhci controller is one of such type, writing
> to this bits is un-supported.
>
> Default value of sdma_buffer_boundary_arg is set to SDHCI_DEFAULT_BOUNDARY_ARG.
>
> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>

There are a couple of minor suggestions below

> ---
> drivers/mmc/host/sdhci.c | 14 ++++++++++----
> drivers/mmc/host/sdhci.h | 3 +++
> 2 files changed, 13 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index ecd0d4350e8a..4a7b5dcfc55b 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -897,7 +897,7 @@ static void sdhci_prepare_data(struct sdhci_host *host, struct mmc_command *cmd)
> sdhci_set_transfer_irqs(host);
>
> /* Set the DMA boundary value and block size */
> - sdhci_writew(host, SDHCI_MAKE_BLKSZ(SDHCI_DEFAULT_BOUNDARY_ARG,
> + sdhci_writew(host, SDHCI_MAKE_BLKSZ(host->sdma_buffer_boundary_arg,
> data->blksz), SDHCI_BLOCK_SIZE);
> sdhci_writew(host, data->blocks, SDHCI_BLOCK_COUNT);
> }
> @@ -2037,6 +2037,7 @@ static void sdhci_send_tuning(struct sdhci_host *host, u32 opcode)
> struct mmc_command cmd = {};
> struct mmc_request mrq = {};
> unsigned long flags;
> + u32 barg = host->sdma_buffer_boundary_arg;

Might as well use a 2-character variable name and avoid the line wrapping
e.g. 'barg' -> 'sb'

>
> spin_lock_irqsave(&host->lock, flags);
>
> @@ -2052,9 +2053,11 @@ static void sdhci_send_tuning(struct sdhci_host *host, u32 opcode)
> */
> if (cmd.opcode == MMC_SEND_TUNING_BLOCK_HS200 &&
> mmc->ios.bus_width == MMC_BUS_WIDTH_8)
> - sdhci_writew(host, SDHCI_MAKE_BLKSZ(7, 128), SDHCI_BLOCK_SIZE);
> + sdhci_writew(host,
> + SDHCI_MAKE_BLKSZ(barg, 128), SDHCI_BLOCK_SIZE);
> else
> - sdhci_writew(host, SDHCI_MAKE_BLKSZ(7, 64), SDHCI_BLOCK_SIZE);
> + sdhci_writew(host,
> + SDHCI_MAKE_BLKSZ(barg, 64), SDHCI_BLOCK_SIZE);
>
> /*
> * The tuning block is sent by the card to the host controller.
> @@ -2998,7 +3001,8 @@ void sdhci_cqe_enable(struct mmc_host *mmc)
> ctrl |= SDHCI_CTRL_ADMA32;
> sdhci_writeb(host, ctrl, SDHCI_HOST_CONTROL);
>
> - sdhci_writew(host, SDHCI_MAKE_BLKSZ(SDHCI_DEFAULT_BOUNDARY_ARG, 512),
> + sdhci_writew(host,
> + SDHCI_MAKE_BLKSZ(host->sdma_buffer_boundary_arg, 512),
> SDHCI_BLOCK_SIZE);
>
> /* Set maximum timeout */
> @@ -3119,6 +3123,8 @@ struct sdhci_host *sdhci_alloc_host(struct device *dev,
>
> host->tuning_delay = -1;
>
> + host->sdma_buffer_boundary_arg = SDHCI_DEFAULT_BOUNDARY_ARG;
> +
> return host;
> }
>
> diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
> index 0469fa191493..6ff2294e55b3 100644
> --- a/drivers/mmc/host/sdhci.h
> +++ b/drivers/mmc/host/sdhci.h
> @@ -541,6 +541,9 @@ struct sdhci_host {
> /* Delay (ms) between tuning commands */
> int tuning_delay;
>
> + /* Host SDMA buffer boundary. */
> + u32 sdma_buffer_boundary_arg;

The name seems a bit long. What about just 'sdma_boundary'?

> +
> unsigned long private[0] ____cacheline_aligned;
> };
>
>