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 <[email protected]> > --- > 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 <[email protected]> <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 [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
