blob: 91b06b19fea1006f8a48a34ac835e1e898b82d64 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
|
From 940ec770c295682993d1cccce3081fd7c74fece8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= <rafal@milecki.pl>
Date: Thu, 11 Oct 2018 09:42:17 +0200
Subject: [PATCH] spi: bcm-qspi: switch back to reading flash using smaller
chunks
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Fixing/optimizing bcm_qspi_bspi_read() performance introduced two
changes:
1) It added a loop to read all requested data using multiple BSPI ops.
2) It bumped max size of a single BSPI block request from 256 to 512 B.
The later change resulted in occasional BSPI timeouts causing a
regression.
For some unknown reason hardware doesn't always handle reads as expected
when using 512 B chunks. In such cases it may happen that BSPI returns
amount of requested bytes without the last 1-3 ones. It provides the
remaining bytes later but doesn't raise an interrupt until another LR
start.
Switching back to 256 B reads fixes that problem and regression.
Fixes: 345309fa7c0c ("spi: bcm-qspi: Fix bcm_qspi_bspi_read() performance")
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org
---
drivers/spi/spi-bcm-qspi.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/spi/spi-bcm-qspi.c
+++ b/drivers/spi/spi-bcm-qspi.c
@@ -88,7 +88,7 @@
#define BSPI_BPP_MODE_SELECT_MASK BIT(8)
#define BSPI_BPP_ADDR_SELECT_MASK BIT(16)
-#define BSPI_READ_LENGTH 512
+#define BSPI_READ_LENGTH 256
/* MSPI register offsets */
#define MSPI_SPCR0_LSB 0x000
|
