mmc: Merge branch fixes into next

Merge the mmc fixes for v6.10-rc[n] into the next branch, to allow them to
get tested together with the new mmc changes that are targeted for v6.11.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

1 files changed, 15 insertions, 0 deletions

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index a20df9383b20..4b91c9e96635 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -4708,6 +4708,21 @@ int sdhci_setup_host(struct sdhci_host *host)
 		if (host->quirks & SDHCI_QUIRK_BROKEN_ADMA_ZEROLEN_DESC) {
 			host->max_adma = 65532; /* 32-bit alignment */
 			mmc->max_seg_size = 65535;
+			/*
+			 * sdhci_adma_table_pre() expects to define 1 DMA
+			 * descriptor per segment, so the maximum segment size
+			 * is set accordingly. SDHCI allows up to 64KiB per DMA
+			 * descriptor (16-bit field), but some controllers do
+			 * not support "zero means 65536" reducing the maximum
+			 * for them to 65535. That is a problem if PAGE_SIZE is
+			 * 64KiB because the block layer does not support
+			 * max_seg_size < PAGE_SIZE, however
+			 * sdhci_adma_table_pre() has a workaround to handle
+			 * that case, and split the descriptor. Refer also
+			 * comment in sdhci_adma_table_pre().
+			 */
+			if (mmc->max_seg_size < PAGE_SIZE)
+				mmc->max_seg_size = PAGE_SIZE;
 		} else {
 			mmc->max_seg_size = 65536;
 		}