On 29/10/2021 14:40, Bough Chen wrote: >> -----Original Message----- >> From: Adrian Hunter [mailto:adrian.hunter@xxxxxxxxx] >> Sent: 2021年10月27日 13:50 >> To: Bough Chen <haibo.chen@xxxxxxx>; ulf.hansson@xxxxxxxxxx >> Cc: linux-mmc@xxxxxxxxxxxxxxx; dl-linux-imx <linux-imx@xxxxxxx> >> Subject: Re: [PATCH] mmc: sdhci: disable ADMA when PAGE SIZE is 64K >> >> On 27/10/2021 05:47, haibo.chen@xxxxxxx wrote: >>> From: Haibo Chen <haibo.chen@xxxxxxx> >>> >>> For ADMA with quirks SDHCI_QUIRK_BROKEN_ADMA_ZEROLEN_DESC, it >> limit >>> the max segment size as 64K-1. Currently, linux kernel support >>> 4K/16K/64K PAGE_SIZE. If choose 64K PAGE_SIZE, sdhci in ADMA mode with >>> the upper quirks will meet issue. >>> >>> Though mmc driver give block layer the max segment size through >>> blk_queue_max_segment_size(), but in this function, it will compare >>> the argument with PAGE_SIZE, and will choose PAGE_SIZE if the argument >>> is smaller than PAGE_SIZE. When PAGE_SIZE is 64K, finally the mmc >>> request queue will get 64K as the max segment size. Once the sg data >>> length=64K, ADMA will meet issue. For this case, need to disable ADMA >>> mode. >> >> Sorry, I didn't look closely enough at this. >> >> For the 64K PAGE_SIZE case, did you try blk_queue_virt_boundary() with a 32K >> mask instead of blk_queue_max_segment_size() ? >> e.g. a hack for testing purposes like this: > > I test on my board, this do not work, I still can see sg data_length = 65536. What about tweaking the logic to write ADMA descriptors? Something like below for instance? diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c index 269c86569402..07c6da1f2f0f 100644 --- a/drivers/mmc/host/sdhci.c +++ b/drivers/mmc/host/sdhci.c @@ -771,7 +771,19 @@ static void sdhci_adma_table_pre(struct sdhci_host *host, len -= offset; } - BUG_ON(len > 65536); + /* + * The block layer forces a minimum segment size of PAGE_SIZE, + * so 'len' can be too big here if PAGE_SIZE >= 64KiB. Write + * multiple descriptors, noting that the ADMA table is sized + * for 4KiB chunks anyway, so it will be big enough. + */ + while (len > host->max_adma) { + int n = 32 * 1024; /* 32KiB*/ + + __sdhci_adma_write_desc(host, &desc, addr, n, ADMA2_TRAN_VALID); + addr += n; + len -= n; + } /* tran, valid */ if (len) @@ -3968,6 +3980,7 @@ struct sdhci_host *sdhci_alloc_host(struct device *dev, * descriptor for each segment, plus 1 for a nop end descriptor. */ host->adma_table_cnt = SDHCI_MAX_SEGS * 2 + 1; + host->max_adma = 65536; host->max_timeout_count = 0xE; @@ -4633,10 +4646,12 @@ int sdhci_setup_host(struct sdhci_host *host) * be larger than 64 KiB though. */ if (host->flags & SDHCI_USE_ADMA) { - if (host->quirks & SDHCI_QUIRK_BROKEN_ADMA_ZEROLEN_DESC) + if (host->quirks & SDHCI_QUIRK_BROKEN_ADMA_ZEROLEN_DESC) { + host->max_adma = 65532; /* 32-bit alignment */ mmc->max_seg_size = 65535; - else + } else { mmc->max_seg_size = 65536; + } } else { mmc->max_seg_size = mmc->max_req_size; } diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h index bb883553d3b4..d7929d725730 100644 --- a/drivers/mmc/host/sdhci.h +++ b/drivers/mmc/host/sdhci.h @@ -340,7 +340,8 @@ struct sdhci_adma2_64_desc { /* * Maximum segments assuming a 512KiB maximum requisition size and a minimum - * 4KiB page size. + * 4KiB page size. Note this also allows enough for multiple descriptors in + * case of PAGE_SIZE >= 64KiB. */ #define SDHCI_MAX_SEGS 128 @@ -543,6 +544,7 @@ struct sdhci_host { unsigned int blocks; /* remaining PIO blocks */ int sg_count; /* Mapped sg entries */ + int max_adma; /* Max. length in ADMA descriptor */ void *adma_table; /* ADMA descriptor table */ void *align_buffer; /* Bounce buffer */ -- 2.25.1 > > Best Regards > Haibo Chen >> >> diff --git a/drivers/mmc/core/queue.c b/drivers/mmc/core/queue.c index >> b15c034b42fb..4c3a9d999500 100644 >> --- a/drivers/mmc/core/queue.c >> +++ b/drivers/mmc/core/queue.c >> @@ -376,8 +376,7 @@ static void mmc_setup_queue(struct mmc_queue *mq, >> struct mmc_card *card) >> * both blk_queue_max_segment_size(). >> */ >> if (!host->can_dma_map_merge) >> - blk_queue_max_segment_size(mq->queue, >> - round_down(host->max_seg_size, block_size)); >> + blk_queue_virt_boundary(mq->queue, 0x7fff); >> >> dma_set_max_seg_size(mmc_dev(host), >> queue_max_segment_size(mq->queue)); >> >> >> >> >>> >>> Signed-off-by: Haibo Chen <haibo.chen@xxxxxxx> >>> --- >>> drivers/mmc/host/sdhci.c | 6 ++++++ >>> 1 file changed, 6 insertions(+) >>> >>> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c index >>> dbe87995596c..47e0c0156b94 100644 >>> --- a/drivers/mmc/host/sdhci.c >>> +++ b/drivers/mmc/host/sdhci.c >>> @@ -4187,6 +4187,12 @@ int sdhci_setup_host(struct sdhci_host *host) >>> host->flags &= ~SDHCI_USE_ADMA; >>> } >>> >>> + if ((host->quirks & SDHCI_QUIRK_BROKEN_ADMA_ZEROLEN_DESC) && >>> + PAGE_SIZE >= 65536 && (host->flags & SDHCI_USE_ADMA)) { >>> + DBG("Disabling ADMA as it don't support >= 64K PAGE_SIZE\n"); >>> + host->flags &= ~SDHCI_USE_ADMA; >>> + } >>> + >>> if (sdhci_can_64bit_dma(host)) >>> host->flags |= SDHCI_USE_64_BIT_DMA; >>> >>> >
