mirror of https://github.com/hak5/openwrt.git
38 lines
1.4 KiB
Diff
38 lines
1.4 KiB
Diff
From 833bfade96561216aa2129516a5926a0326860a2 Mon Sep 17 00:00:00 2001
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From: Hauke Mehrtens <hauke@hauke-m.de>
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Date: Mon, 17 Apr 2017 01:38:05 +0200
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Subject: spi: double time out tolerance
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The generic SPI code calculates how long the issued transfer would take
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and adds 100ms in addition to the timeout as tolerance. On my 500 MHz
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Lantiq Mips SoC I am getting timeouts from the SPI like this when the
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system boots up:
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m25p80 spi32766.4: SPI transfer timed out
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blk_update_request: I/O error, dev mtdblock3, sector 2
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SQUASHFS error: squashfs_read_data failed to read block 0x6e
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After increasing the tolerance for the timeout to 200ms I haven't seen
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these SPI transfer time outs any more.
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The Lantiq SPI driver in use here has an extra work queue in between,
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which gets triggered when the controller send the last word and the
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hardware FIFOs used for reading and writing are only 8 words long.
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Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
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Signed-off-by: Mark Brown <broonie@kernel.org>
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---
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drivers/spi/spi.c | 2 +-
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1 file changed, 1 insertion(+), 1 deletion(-)
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--- a/drivers/spi/spi.c
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+++ b/drivers/spi/spi.c
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@@ -1004,7 +1004,7 @@ static int spi_transfer_one_message(stru
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ret = 0;
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ms = 8LL * 1000LL * xfer->len;
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do_div(ms, xfer->speed_hz);
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- ms += ms + 100; /* some tolerance */
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+ ms += ms + 200; /* some tolerance */
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if (ms > UINT_MAX)
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ms = UINT_MAX;
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