The commit de3ee99b097d ("mmc: Delete bounce buffer handling") deletes the
bounce buffer handling, but also causes the max_req_size for sdhci to be
increased, in case when max_segs == 1. This causes errors for sdhci-pci
Ricoh variant, about the swiotlb buffer to become full.
Fix the issue, by taking IO_TLB_SEGSIZE and IO_TLB_SHIFT into account when
deciding the max_req_size for sdhci.
Reported-by: Jiri Slaby <jslaby@xxxxxxx>
Fixes: de3ee99b097d ("mmc: Delete bounce buffer handling")
Cc: <stable@xxxxxxxxxxxxxxx> # v4.14+
Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
Tested-by: Jiri Slaby <jslaby@xxxxxxx>
---
drivers/mmc/host/sdhci.c | 28 ++++++++++++++++++----------
1 file changed, 18 insertions(+), 10 deletions(-)
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 2f14334..e9290a3 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -21,6 +21,7 @@
#include <linux/dma-mapping.h>
#include <linux/slab.h>
#include <linux/scatterlist.h>
+#include <linux/swiotlb.h>
#include <linux/regulator/consumer.h>
#include <linux/pm_runtime.h>
#include <linux/of.h>
@@ -3651,22 +3652,29 @@ int sdhci_setup_host(struct sdhci_host *host)
spin_lock_init(&host->lock);
/*
+ * Maximum number of sectors in one transfer. Limited by SDMA boundary
+ * size (512KiB). Note some tuning modes impose a 4MiB limit, but this
+ * is less anyway.
+ */
+ mmc->max_req_size = 524288;
+
+ /*
* Maximum number of segments. Depends on if the hardware
* can do scatter/gather or not.
*/
- if (host->flags & SDHCI_USE_ADMA)
+ if (host->flags & SDHCI_USE_ADMA) {
mmc->max_segs = SDHCI_MAX_SEGS;
- else if (host->flags & SDHCI_USE_SDMA)
+ } else if (host->flags & SDHCI_USE_SDMA) {
mmc->max_segs = 1;
- else /* PIO */
+ if (swiotlb_max_segment()) {
+ unsigned int max_req_size = (1 << IO_TLB_SHIFT) *
+ IO_TLB_SEGSIZE;
+ mmc->max_req_size = min(mmc->max_req_size,
+ max_req_size);
+ }
+ } else { /* PIO */
mmc->max_segs = SDHCI_MAX_SEGS;
-
- /*
- * Maximum number of sectors in one transfer. Limited by SDMA boundary
- * size (512KiB). Note some tuning modes impose a 4MiB limit, but this
- * is less anyway.
- */
- mmc->max_req_size = 524288;
+ }
/*
* Maximum segment size. Could be one segment with the maximum number
--
2.7.4