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| author | Shawn Lin <shawn.lin@rock-chips.com> | 2026-05-29 09:17:39 +0800 |
|---|---|---|
| committer | Ulf Hansson <ulfh@kernel.org> | 2026-05-29 15:12:51 +0200 |
| commit | b99062da21a3988c6b8f1ed0730bf3587cdc7844 (patch) | |
| tree | e4b8e6d1f5bcb94ac328dab02b7ec5e289b8f627 /drivers | |
| parent | 94044acc20cdb99a0429723bcca5e1d828dbf47f (diff) | |
| download | linux-next-history-b99062da21a3988c6b8f1ed0730bf3587cdc7844.tar.gz | |
mmc: dw_mmc: Add desc_num field for clarity
The ring_size field in struct dw_mci is misleadingly named.
Despite its name, it does not represent the size of the descriptor
ring buffer in bytes, but rather the number of descriptors allocated
within the fixed-size ring buffer.
The actual ring buffer size is fixed at PAGE_SIZE (or DESC_RING_BUF_SZ,
which equals PAGE_SIZE). Within this buffer, we allocate either
struct idmac_desc or struct idmac_desc_64addr descriptors, and
ring_size stores the count of these descriptors.
This naming has caused confusion, as it's also used to set
mmc->max_segs (the maximum number of scatter-gather segments),
which logically corresponds to the number of descriptors, not a
size in bytes.
No functional change is introduced by this naming-only patch.
Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: Ulf Hansson <ulfh@kernel.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/mmc/host/dw_mmc.c | 16 | ||||
| -rw-r--r-- | drivers/mmc/host/dw_mmc.h | 4 |
2 files changed, 10 insertions, 10 deletions
diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c index 3b4157f34d11f..d734d010444dd 100644 --- a/drivers/mmc/host/dw_mmc.c +++ b/drivers/mmc/host/dw_mmc.c @@ -490,12 +490,12 @@ static int dw_mci_idmac_init(struct dw_mci *host) if (host->dma_64bit_address == 1) { struct idmac_desc_64addr *p; - /* Number of descriptors in the ring buffer */ - host->ring_size = + + host->desc_num = DESC_RING_BUF_SZ / sizeof(struct idmac_desc_64addr); /* Forward link the descriptor list */ - for (i = 0, p = host->sg_cpu; i < host->ring_size - 1; + for (i = 0, p = host->sg_cpu; i < host->desc_num - 1; i++, p++) { p->des6 = (host->sg_dma + (sizeof(struct idmac_desc_64addr) * @@ -518,13 +518,13 @@ static int dw_mci_idmac_init(struct dw_mci *host) } else { struct idmac_desc *p; - /* Number of descriptors in the ring buffer */ - host->ring_size = + + host->desc_num = DESC_RING_BUF_SZ / sizeof(struct idmac_desc); /* Forward link the descriptor list */ for (i = 0, p = host->sg_cpu; - i < host->ring_size - 1; + i < host->desc_num - 1; i++, p++) { p->des3 = cpu_to_le32(host->sg_dma + (sizeof(struct idmac_desc) * (i + 1))); @@ -2857,10 +2857,10 @@ static int dw_mci_init_host(struct dw_mci *host) /* Useful defaults if platform data is unset. */ if (host->use_dma == TRANS_MODE_IDMAC) { - mmc->max_segs = host->ring_size; + mmc->max_segs = host->desc_num; mmc->max_blk_size = 65535; mmc->max_seg_size = 0x1000; - mmc->max_req_size = mmc->max_seg_size * host->ring_size; + mmc->max_req_size = mmc->max_seg_size * host->desc_num; mmc->max_blk_count = mmc->max_req_size / 512; } else if (host->use_dma == TRANS_MODE_EDMAC) { mmc->max_segs = 64; diff --git a/drivers/mmc/host/dw_mmc.h b/drivers/mmc/host/dw_mmc.h index 2ce8585e2c1e5..9ffcd3946cffb 100644 --- a/drivers/mmc/host/dw_mmc.h +++ b/drivers/mmc/host/dw_mmc.h @@ -79,7 +79,7 @@ struct dw_mci_dma_slave { * @dma_ops: Pointer to DMA callbacks. * @cmd_status: Snapshot of SR taken upon completion of the current * command. Only valid when EVENT_CMD_COMPLETE is pending. - * @ring_size: Buffer size for idma descriptors. + * @desc_num: Number of idmac descriptors available. * @dms: structure of slave-dma private data. * @phy_regs: physical address of controller's register map * @data_status: Snapshot of SR taken upon completion of the current @@ -186,7 +186,7 @@ struct dw_mci { void *sg_cpu; const struct dw_mci_dma_ops *dma_ops; /* For idmac */ - unsigned int ring_size; + unsigned short desc_num; /* For edmac */ struct dw_mci_dma_slave *dms; |