On Mon, Jan 22, 2018 at 7:18 AM, Benjamin Beckmeyer
<beckmeyer.b@xxxxxxxxx> wrote:
> I tested it a few moments ago and to make it short: it doesn't work.
Annoying ... since the i.MX and x86 PCI version so clearly differs
here I'm left to trial and error over the mailing list.
> mmc1 bounce up to 128 segments into one, max segment size 65536 bytes
> mmc1: SDHCI controller on 53fb8000.esdhc [53fb8000.esdhc] using DMA
Could it be that this SDMA has this problem of not being
able to send things aligned on even 64K pages? (Off-by-one
error in the hardware.)
Could you try this on top of the patch?
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 25b5e598ee6d..6b436f0e0925 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -3323,7 +3323,7 @@ static int sdhci_allocate_bounce_buffer(struct
sdhci_host *host)
* has diminishing returns, this is probably because SD/MMC
* cards are usually optimized to handle this size of requests.
*/
- bounce_size = SZ_64K;
+ bounce_size = SZ_64K-1;
/*
* Adjust downwards to maximum request size if this is less
* than our segment size, else hammer down the maximum
The code should report that it bounces 127 segments into 1 instead.
Yours,
Linus Walleij