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44 lines
1.6 KiB
44 lines
1.6 KiB
From cf5cb87ad3bd6549cc18aa880bfadd3707c75f93 Mon Sep 17 00:00:00 2001
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From: Martin Sperl <kernel@martin.sperl.org>
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Date: Thu, 10 Sep 2015 09:32:14 +0000
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Subject: [PATCH 182/222] backport: spi: bcm2835: BUG: fix wrong use of
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PAGE_MASK
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There is a bug in the alignment checking of transfers,
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that results in DMA not being used for un-aligned
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transfers that do not cross page-boundries, which is valid.
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This is due to a missconception of the meaning PAGE_MASK
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when implementing that check originally - (PAGE_SIZE - 1)
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should have been used instead.
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Also fixes a copy/paste error.
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Reported-by: <robert@axium.co.nz>
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Signed-off-by: Martin Sperl <kernel@martin.sperl.org>
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Signed-off-by: Mark Brown <broonie@kernel.org>
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Cc: stable@vger.kernel.org
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---
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drivers/spi/spi-bcm2835.c | 6 +++---
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1 file changed, 3 insertions(+), 3 deletions(-)
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--- a/drivers/spi/spi-bcm2835.c
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+++ b/drivers/spi/spi-bcm2835.c
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@@ -386,14 +386,14 @@ static bool bcm2835_spi_can_dma(struct s
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/* otherwise we only allow transfers within the same page
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* to avoid wasting time on dma_mapping when it is not practical
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*/
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- if (((size_t)tfr->tx_buf & PAGE_MASK) + tfr->len > PAGE_SIZE) {
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+ if (((size_t)tfr->tx_buf & (PAGE_SIZE - 1)) + tfr->len > PAGE_SIZE) {
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dev_warn_once(&spi->dev,
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"Unaligned spi tx-transfer bridging page\n");
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return false;
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}
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- if (((size_t)tfr->rx_buf & PAGE_MASK) + tfr->len > PAGE_SIZE) {
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+ if (((size_t)tfr->rx_buf & (PAGE_SIZE - 1)) + tfr->len > PAGE_SIZE) {
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dev_warn_once(&spi->dev,
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- "Unaligned spi tx-transfer bridging page\n");
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+ "Unaligned spi rx-transfer bridging page\n");
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return false;
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}
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