On 11/21/2017, 04:08 PM, Ulf Hansson wrote:
> Subject: [PATCH] mmc: sdhci: Fix bounce buffer overflow
...
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
...
> @@ -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;
It seems to work fine. FWIW the debug output is:
[ 0.708312] mmc0: max_segs=1 max_req_size=262144 h->flags=00004001
thanks,
--
js
suse labs
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