From mboxrd@z Thu Jan 1 00:00:00 1970 From: fisaksen@baylibre.com (Frode Isaksen) Date: Thu, 23 Feb 2017 19:02:00 +0100 Subject: [PATCH v3 5/6] spi: davinci: do not use DMA for vmalloc'ed buffers In-Reply-To: <1487872921-26628-1-git-send-email-fisaksen@baylibre.com> References: <1487872921-26628-1-git-send-email-fisaksen@baylibre.com> Message-ID: <1487872921-26628-6-git-send-email-fisaksen@baylibre.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Using vmalloc'ed buffers will fail since daVinci has VIVT cache and only the kernel lowmem virtual address is invalidated/flushed when performing DMA. The virtual address returned from vmalloc() is not invalidated/flushed and may contain stale data when returning from spi_sync(). Fixes errors when running UBIFS over SPI NOR. Revert this when all upper layer users of vmalloc'ed buffers sent to SPI handles cache flushing/invalidating. Signed-off-by: Frode Isaksen --- drivers/spi/spi-davinci.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/spi/spi-davinci.c b/drivers/spi/spi-davinci.c index 75c658e..f37bbdd 100644 --- a/drivers/spi/spi-davinci.c +++ b/drivers/spi/spi-davinci.c @@ -482,7 +482,9 @@ static bool davinci_spi_can_dma(struct spi_master *master, if (spicfg) can_dma = (spicfg->io_type == SPI_IO_TYPE_DMA) && - (xfer->len >= DMA_MIN_BYTES); + (xfer->len >= DMA_MIN_BYTES) && + !is_vmalloc_addr(xfer->rx_buf) && + !is_vmalloc_addr(xfer->tx_buf); return can_dma; } -- 2.7.4