On Thu, 29 Apr 2021 at 22:30, Bean Huo huobean@gmail.com wrote:
On Fri, 2021-03-19 at 16:42 +0100, Bean Huo wrote:
On Fri, 2021-03-19 at 15:09 +0100, Ulf Hansson wrote:
On Fri, 19 Mar 2021 at 13:14, Bean Huo huobean@gmail.com wrote:
From: Bean Huo beanhuo@micron.com Currently, we have two ways to issue multiple-block read/write the command to the eMMC. One is by normal IO request path fs->block-
mmc.
Another one is that we can issue multiple-block read/write through MMC ioctl interface. For the first path, mrq->stop, and mrq-
stop- opcode
will be initialized in mmc_blk_data_prep(). However, for the second IO path, mrq->stop is not initialized since it is a pre-defined multiple blocks read/write.
As a matter of fact this way is also supported for the regular block I/O path. To make the mmc block driver to use it, mmc host drivers need to announce that it's supported by setting MMC_CAP_CMD23. It looks like that is what your patch should be targeted towards, can you have a look at this instead?
Hi Ulf,
Thanks for your comments. I will look at that as your suggestion.
The patch [1/2] is accepted, so I will just update this patch to
the next version.
Kind regards,
Bean
Hi Uffe, Could you please firstly accept this patch? let the customer update their kernel. As I tried to develop the next version of the patch according to your suggestion, more changes will be involved. Also, no matter how to make the change general, below mrq->stop checkup should be deleted since it is obsolete. In the data transmission completion interrupt, mrq->stop will be checked again.
if (!mrq->data || !mrq->data->sg || !mrq->data->sg_len ||!mrq->stop || mrq->stop->opcode != MMC_STOP_TRANSMISSION) {
if (!mrq->data || !mrq->data->sg || !mrq->data->sg_len) {
Well, I don't think the above checks are incorrect. Instead I think it points out that the cavium mmc driver lacks support for CMD23, while only open ended data transfers are supported.
The proper way forward is instead to implement CMD23 support to the cavium mmc driver. In the same patch adding that support, you should be able to remove the above checks.
Kind regards Uffe