Hi Johan,
On Wed, Nov 23 2011, Johan Rudholm wrote:
> If the read or write buffer size associated with the command sent
> through the mmc_blk_ioctl is zero, do not prepare data buffer.
>
> This enables a ioctl(2) call to for instance send a MMC_SWITCH to set
> a byte in the ext_csd.
>
> Change-Id: Ieab8400ace1ba91bfb3d911377de557bf2d593d0
(Please don't send these tags; I've stripped this one out.)
> Signed-off-by: Johan Rudholm <johan.rudholm@xxxxxxxxxxxxxx>
> ---
> drivers/mmc/card/block.c | 82 +++++++++++++++++++++++++---------------------
> 1 files changed, 45 insertions(+), 37 deletions(-)
>
> diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
> index 12096cc..4d29b30 100644
> --- a/drivers/mmc/card/block.c
> +++ b/drivers/mmc/card/block.c
> @@ -336,6 +336,9 @@ static struct mmc_blk_ioc_data *mmc_blk_ioctl_copy_from_user(
> goto idata_err;
> }
>
> + if (!idata->buf_bytes)
> + return idata;
> +
> idata->buf = kzalloc(idata->buf_bytes, GFP_KERNEL);
> if (!idata->buf) {
> err = -ENOMEM;
> @@ -382,25 +385,6 @@ static int mmc_blk_ioctl_cmd(struct block_device *bdev,
> if (IS_ERR(idata))
> return PTR_ERR(idata);
>
> - cmd.opcode = idata->ic.opcode;
> - cmd.arg = idata->ic.arg;
> - cmd.flags = idata->ic.flags;
> -
> - data.sg = &sg;
> - data.sg_len = 1;
> - data.blksz = idata->ic.blksz;
> - data.blocks = idata->ic.blocks;
> -
> - sg_init_one(data.sg, idata->buf, idata->buf_bytes);
> -
> - if (idata->ic.write_flag)
> - data.flags = MMC_DATA_WRITE;
> - else
> - data.flags = MMC_DATA_READ;
> -
> - mrq.cmd = &cmd;
> - mrq.data = &data;
> -
> md = mmc_blk_get(bdev->bd_disk);
> if (!md) {
> err = -EINVAL;
> @@ -413,6 +397,48 @@ static int mmc_blk_ioctl_cmd(struct block_device *bdev,
> goto cmd_done;
> }
>
> + cmd.opcode = idata->ic.opcode;
> + cmd.arg = idata->ic.arg;
> + cmd.flags = idata->ic.flags;
> +
> + if (idata->buf_bytes) {
> + data.sg = &sg;
> + data.sg_len = 1;
> + data.blksz = idata->ic.blksz;
> + data.blocks = idata->ic.blocks;
> +
> + sg_init_one(data.sg, idata->buf, idata->buf_bytes);
> +
> + if (idata->ic.write_flag)
> + data.flags = MMC_DATA_WRITE;
> + else
> + data.flags = MMC_DATA_READ;
> +
> + /* data.flags must already be set before doing this. */
> + mmc_set_data_timeout(&data, card);
> +
> + /* Allow overriding the timeout_ns for empirical tuning. */
> + if (idata->ic.data_timeout_ns)
> + data.timeout_ns = idata->ic.data_timeout_ns;
> +
> + if ((cmd.flags & MMC_RSP_R1B) == MMC_RSP_R1B) {
> + /*
> + * Pretend this is a data transfer and rely on the
> + * host driver to compute timeout. When all host
> + * drivers support cmd.cmd_timeout for R1B, this
> + * can be changed to:
> + *
> + * mrq.data = NULL;
> + * cmd.cmd_timeout = idata->ic.cmd_timeout_ms;
> + */
> + data.timeout_ns = idata->ic.cmd_timeout_ms * 1000000;
> + }
> +
> + mrq.data = &data;
> + }
> +
> + mrq.cmd = &cmd;
> +
> mmc_claim_host(card->host);
>
> if (idata->ic.is_acmd) {
> @@ -421,24 +447,6 @@ static int mmc_blk_ioctl_cmd(struct block_device *bdev,
> goto cmd_rel_host;
> }
>
> - /* data.flags must already be set before doing this. */
> - mmc_set_data_timeout(&data, card);
> - /* Allow overriding the timeout_ns for empirical tuning. */
> - if (idata->ic.data_timeout_ns)
> - data.timeout_ns = idata->ic.data_timeout_ns;
> -
> - if ((cmd.flags & MMC_RSP_R1B) == MMC_RSP_R1B) {
> - /*
> - * Pretend this is a data transfer and rely on the host driver
> - * to compute timeout. When all host drivers support
> - * cmd.cmd_timeout for R1B, this can be changed to:
> - *
> - * mrq.data = NULL;
> - * cmd.cmd_timeout = idata->ic.cmd_timeout_ms;
> - */
> - data.timeout_ns = idata->ic.cmd_timeout_ms * 1000000;
> - }
> -
> mmc_wait_for_req(card->host, &mrq);
>
> if (cmd.error) {
Thanks, looks good to me, pushed to mmc-next for 3.3.
Would you be able to share the userspace code that you've been using
with this, please? I'd like to start collecting a repository of
userspace code showing common uses of this ioctl.
- Chris.
--
Chris Ball <cjb@xxxxxxxxxx> <http://printf.net/>
One Laptop Per Child
--
To unsubscribe from this list: send the line "unsubscribe linux-mmc" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
