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SubjectRe: [PATCH] mmc: cqhci: data size depending on queue depth
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On 15/01/19 9:13 PM, Alamy Liu wrote:
> CQE_DCMD is not necessary to be enabled when CQE is enabled.
> (Software could halt CQE to send command, or via DCMD)
>
> In the case that CQE_DCMD is not enabled, it still needs to allocate
> space for data transfer. For instance:
> CQE_DCMD is enabled: 32 slots space
> CQE_DCMD is disabled: 31 slots space (is good enough)

Is that the right way around?

If DCMD is enabled then we need 31 slots for data transfer and 1 for DCMD.
If DCMD is disabled then we need 32 slots for data transfer.

>
> Signed-off-by: Alamy Liu <alamy.liu@gmail.com>
> ---
> drivers/mmc/host/cqhci.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/mmc/host/cqhci.c b/drivers/mmc/host/cqhci.c
> index 4cc7863c13..974997b6cb 100644
> --- a/drivers/mmc/host/cqhci.c
> +++ b/drivers/mmc/host/cqhci.c
> @@ -202,7 +202,7 @@ static int cqhci_host_alloc_tdl(struct cqhci_host *cq_host)
> cq_host->desc_size = cq_host->slot_sz * cq_host->num_slots;
>
> cq_host->data_size = cq_host->trans_desc_len * cq_host->mmc->max_segs *
> - (cq_host->num_slots - 1);
> + cq_host->mmc->cqe_qdepth;

So there is not enough being allocated for the !(mmc->caps2 &
MMC_CAP2_CQE_DCMD) case, which means this is a fix? In that case, please
add a fixes tag, cc stable, and make the commit message clear that this is a
fix.

>
> pr_debug("%s: cqhci: desc_size: %zu data_sz: %zu slot-sz: %d\n",
> mmc_hostname(cq_host->mmc), cq_host->desc_size, cq_host->data_size,
>

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