[PATCH V3] mmc: sdhci: Let a vendor driver supply and update ADMA descriptor size

[Veerabhadrarao Badiganti]

Let a vendor driver supply the maximum descriptor size that it
can operate on. ADMA descriptor table would be allocated using this
supplied size.
If any SD Host controller is of version prior to v4.10 spec
but supports 16byte descriptor, this change allows them to supply
correct descriptor size for ADMA table allocation.

Also let a vendor driver update the descriptor size by overriding
sdhc_host->desc_size if it has to operates on a different descriptor
sizes in different conditions.

Suggested-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Signed-off-by: Veerabhadrarao Badiganti <vbadigan@xxxxxxxxxxxxxx>
Acked-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
--
Thanks Adrian.

Hi Ulf,
Can you pick this patch instead of earlier one? This is more clean
change, sorry for the multiple interations.
Otherwise let me know, I will make these changes as seperate patch.
---
 drivers/mmc/host/sdhci.c | 16 +++++++---------
 drivers/mmc/host/sdhci.h |  3 ++-
 2 files changed, 9 insertions(+), 10 deletions(-)

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 3140fe2..7a7a18e 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -3821,15 +3821,13 @@ int sdhci_setup_host(struct sdhci_host *host)
 		dma_addr_t dma;
 		void *buf;
 
-		if (host->flags & SDHCI_USE_64_BIT_DMA) {
-			host->adma_table_sz = host->adma_table_cnt *
-					      SDHCI_ADMA2_64_DESC_SZ(host);
-			host->desc_sz = SDHCI_ADMA2_64_DESC_SZ(host);
-		} else {
-			host->adma_table_sz = host->adma_table_cnt *
-					      SDHCI_ADMA2_32_DESC_SZ;
-			host->desc_sz = SDHCI_ADMA2_32_DESC_SZ;
-		}
+		if (!(host->flags & SDHCI_USE_64_BIT_DMA))
+			host->alloc_desc_sz = SDHCI_ADMA2_32_DESC_SZ;
+		else if (!host->alloc_desc_sz)
+			host->alloc_desc_sz = SDHCI_ADMA2_64_DESC_SZ(host);
+
+		host->desc_sz = host->alloc_desc_sz;
+		host->adma_table_sz = host->adma_table_cnt * host->desc_sz;
 
 		host->align_buffer_sz = SDHCI_MAX_SEGS * SDHCI_ADMA2_ALIGN;
 		/*
diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index 0ed3e0e..10bda3a 100644
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -554,7 +554,8 @@ struct sdhci_host {
 	dma_addr_t adma_addr;	/* Mapped ADMA descr. table */
 	dma_addr_t align_addr;	/* Mapped bounce buffer */
 
-	unsigned int desc_sz;	/* ADMA descriptor size */
+	unsigned int desc_sz;	/* ADMA current descriptor size */
+	unsigned int alloc_desc_sz;	/* ADMA descr. max size host supports */
 
 	struct workqueue_struct *complete_wq;	/* Request completion wq */
 	struct work_struct	complete_work;	/* Request completion work */
-- 
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