From mboxrd@z Thu Jan 1 00:00:00 1970 From: akpm@linux-foundation.org (Andrew Morton) Date: Wed, 12 May 2010 14:19:29 -0700 Subject: [PATCH] MMC: at91_mci: modify cache flush routines In-Reply-To: <1273597793-28104-1-git-send-email-nicolas.ferre@atmel.com> References: <20100511134409.GB27201@n2100.arm.linux.org.uk> <1273597793-28104-1-git-send-email-nicolas.ferre@atmel.com> Message-ID: <20100512141929.80c13953.akpm@linux-foundation.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Tue, 11 May 2010 19:09:53 +0200 Nicolas Ferre wrote: > As we were using an internal dma flushing routine, this patch changes to the > DMA API flush_kernel_dcache_page(). Driver is able to compile now. > > Signed-off-by: Nicolas Ferre > --- > drivers/mmc/host/at91_mci.c | 2 +- > 1 files changed, 1 insertions(+), 1 deletions(-) > > diff --git a/drivers/mmc/host/at91_mci.c b/drivers/mmc/host/at91_mci.c > index a6dd7da..813d208 100644 > --- a/drivers/mmc/host/at91_mci.c > +++ b/drivers/mmc/host/at91_mci.c > @@ -315,7 +315,7 @@ static void at91_mci_post_dma_read(struct at91mci_host *host) > } > > kunmap_atomic(sgbuffer, KM_BIO_SRC_IRQ); > - dmac_flush_range((void *)sgbuffer, ((void *)sgbuffer) + amount); > + flush_kernel_dcache_page(sg_page(sg)); > data->bytes_xfered += amount; > if (size == 0) > break; The flush_kernel_dcache_page() documentation specifically says that thou shalt run flush_kernel_dcache_page() _prior_ to kunmapping the page. I don't know if that makes a difference in the real world, but heck why not: --- a/drivers/mmc/host/at91_mci.c~mmc-at91_mci-modify-cache-flush-routines-fix +++ a/drivers/mmc/host/at91_mci.c @@ -314,8 +314,8 @@ static void at91_mci_post_dma_read(struc dmabuf = (unsigned *)tmpv; } - kunmap_atomic(sgbuffer, KM_BIO_SRC_IRQ); flush_kernel_dcache_page(sg_page(sg)); + kunmap_atomic(sgbuffer, KM_BIO_SRC_IRQ); data->bytes_xfered += amount; if (size == 0) break; _ However, I'm wondering why you chose flush_kernel_dcache_page() instead of plain old flush_dcache_page(). Is this a pagecache or possibly direct-io page we're dealing with here?