[PATCH] mmc: sdhci: Remove redundant ADMA page boundary warnings

[PATCH] mmc: sdhci: Remove redundant ADMA page boundary warnings

[Andrew Gabbasov]

The bounce buffer, used for misaligned bytes for ADMA access,
resides wholly within the (align_sz)-aligned word, just by construction.
The page addresses are aligned to (align_sz), either for 4 or 8 bytes
alignment, so that the aligned word resides wholly within a single page
and can't cross the page boundary. So, the bounce buffer can't cross
the page boundary too. That's why the warnings are never hit, and can
be safely removed.

Signed-off-by: Andrew Gabbasov <andrew_gabbasov@mentor.com>
---
 drivers/mmc/host/sdhci.c | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index cbb245b..9dc2770 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -533,8 +533,6 @@ static int sdhci_adma_table_pre(struct sdhci_host *host,
 		if (offset) {
 			if (data->flags & MMC_DATA_WRITE) {
 				buffer = sdhci_kmap_atomic(sg, &flags);
-				WARN_ON(((long)buffer & (PAGE_SIZE - 1)) >
-					(PAGE_SIZE - offset));
 				memcpy(align, buffer, offset);
 				sdhci_kunmap_atomic(buffer, &flags);
 			}
@@ -641,8 +639,6 @@ static void sdhci_adma_table_post(struct sdhci_host *host,
 				       (sg_dma_address(sg) & host->align_mask);
 
 				buffer = sdhci_kmap_atomic(sg, &flags);
-				WARN_ON(((long)buffer & (PAGE_SIZE - 1)) >
-					(PAGE_SIZE - size));
 				memcpy(buffer, align, size);
 				sdhci_kunmap_atomic(buffer, &flags);
 
-- 
2.1.0

Re: [PATCH] mmc: sdhci: Remove redundant ADMA page boundary warnings

[Ulf Hansson]

On 22 December 2014 at 13:23, Andrew Gabbasov
<andrew_gabbasov@mentor.com> wrote:
> The bounce buffer, used for misaligned bytes for ADMA access,
> resides wholly within the (align_sz)-aligned word, just by construction.
> The page addresses are aligned to (align_sz), either for 4 or 8 bytes
> alignment, so that the aligned word resides wholly within a single page
> and can't cross the page boundary. So, the bounce buffer can't cross
> the page boundary too. That's why the warnings are never hit, and can
> be safely removed.
>
> Signed-off-by: Andrew Gabbasov <andrew_gabbasov@mentor.com>

Thanks! Applied for next.

Kind regards
Uffe

> ---
>  drivers/mmc/host/sdhci.c | 4 ----
>  1 file changed, 4 deletions(-)
>
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index cbb245b..9dc2770 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -533,8 +533,6 @@ static int sdhci_adma_table_pre(struct sdhci_host *host,
>                 if (offset) {
>                         if (data->flags & MMC_DATA_WRITE) {
>                                 buffer = sdhci_kmap_atomic(sg, &flags);
> -                               WARN_ON(((long)buffer & (PAGE_SIZE - 1)) >
> -                                       (PAGE_SIZE - offset));
>                                 memcpy(align, buffer, offset);
>                                 sdhci_kunmap_atomic(buffer, &flags);
>                         }
> @@ -641,8 +639,6 @@ static void sdhci_adma_table_post(struct sdhci_host *host,
>                                        (sg_dma_address(sg) & host->align_mask);
>
>                                 buffer = sdhci_kmap_atomic(sg, &flags);
> -                               WARN_ON(((long)buffer & (PAGE_SIZE - 1)) >
> -                                       (PAGE_SIZE - size));
>                                 memcpy(buffer, align, size);
>                                 sdhci_kunmap_atomic(buffer, &flags);
>
> --
> 2.1.0
>
> --
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