Re: [BUG] Rockchip SPI: long burst writes produce unexpected result

From: Vicente Bergas
Date: Sat Apr 06 2019 - 18:23:52 EST

Hi again,
just found the first offending commit:

commit eff0275e5253604429aedc42b008c5fcaa6cc597
Date: Wed Oct 31 11:57:06 2018 +0100

spi: rockchip: simplify use_dma logic
We only need to know if we're using dma when setting
up the transfer, so just use a local variable for
that.

It was mainlined in Linux v5.0.

This is the result of a binary search among this list of commits:
04290192f7ebe892828f69ac57c4684e25da378d
65498c6ae2414a1425aa6c4231e79e2998afec05
01b59ce5dac856323a0c13c1d51d99a819f32efe
74b7efa82b11914c21e30d987ed61d3daa57ff21
420b82f842941a32adf309ca1b193adfc77616b0
eff0275e5253604429aedc42b008c5fcaa6cc597
d790c342e689ea77a5cf72d5b993299911ee5276
eee06a9ee2cd5deaddc5f77ce8f6118c8b82b2a0
fc1ad8ee33480bdf0493b54907b74538bf9b75b8
ce386100d99976442093ff57b5b24a9562c6cc27
fab3e4871f623c8f86e8a0e00749f1480ffa08db
2410d6a3c3070e205169a1a741aa78898e30a642
31bcb57be12fd815a9051f07d64334809b8cb472
30688e4e670d21126aa596df4523940e2f8d24de
a3c174021ce780f5d2e9b2105e2cb4903a37226d
d9071b7e9fc474e474e3b865428a8d30d88daaf4
f340b920511a666b02d371e88801d3817ea7a880
058f7c509e84abd36f988d4e16432366bd793d8f
dcfc861d24ec19f0d0d3d55bb016646794571fbb
dd8fd2cbc73f8650f651da71fc61a6e4f30c1566

Regards,
VicenÃ.

On Saturday, April 6, 2019 7:34:32 PM CEST, Vicente Bergas wrote:
Hi,
i have been experiencing issues writing to NOR-Flash SPI Memories
from two RK3399-based platforms: gru-kevin and sapphire board.
For kevin, this resulted in a bricked device because that memory
is the only boot device.
Fortunately an external programmer is available.

In order to isolate where the issue can be, several tests have been
done, after which it makes me think the issue is related to the
Rockchip SPI driver.

4KB burst reads work fine.
The issue is only observed on the write burst length.

Test user user/kernel kernel RK3399 Num space interface space SoC Status Notes --------------------------------------------------------
1 flashrom linux_mtd MTD/RKspi RKspi Fail
2 flashrom linux_spi RKspi RKspi Fail
3 flashrom linux_spi spi_gpio GPIO OK
4 custom linux_spi spi_gpio GPIO OK 260-byte burst writes
5 custom linux_spi RKspi RKspi Fail 260-byte burst writes
6 custom linux_spi RKspi RKspi OK 1-byte burst writes
7 custom linux_spi RKspi RKspi OK 47-byte burst writes
8 custom linux_spi RKspi RKspi Fail 48-byte burst writes

3, 4) Unaccetably slow, device tree is
spi_gpio {
compatible = "spi-gpio";
#address-cells = <1>;
#size-cells = <0>;
cs-gpios = <&gpio1 RK_PB2 GPIO_ACTIVE_HIGH>;
sck-gpios = <&gpio1 RK_PB1 GPIO_ACTIVE_HIGH>;
mosi-gpios = <&gpio1 RK_PB0 GPIO_ACTIVE_HIGH>;
miso-gpios = <&gpio1 RK_PA7 GPIO_ACTIVE_HIGH>;
num-chipselects = <1>;
spidev@0 {
compatible = "spidev";
reg = <0>;
spi-max-frequency = <50000000>;
};
};
2, 5, 6, 7, 8) device tree is
&spi1 {
status = "okay";
spidev@0 {
compatible = "spidev";
reg = <0>;
spi-max-frequency = <50000000>;
};
};
5, 6, 7, 8) Burst writes are performed this way
enum { BURST = 48 };
struct spi_ioc_transfer msg[0x105];
unsigned i = 0;
for (unsigned j = 0; j < wcnt; j += BURST) {
msg[i++] = { .tx_buf = warr, .len = BURST<wcnt-j ? BURST : wcnt-j };
warr += BURST;
}
if (rcnt)
msg[i++] = { .rx_buf = rarr, .len = rcnt };
ioctl(fd, SPI_IOC_MESSAGE(i), msg);
1, 2, 5, 8) I have no logic analyzer to see what is happenning on the
SPI bus, but when it fails at 48-byte bursts, the contents of the memory
are like this:
Addr Expected Actual
000 FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
010 FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
020 FF FF FF FF FF FF FF FF FF FF FF FF F1 F2 F3 F4 FF FF FF FF FF FF FF FF FF F1 F2 F3 F4 FF FF FF
030 FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
040 FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
050 FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
060 FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
070 FF FF FF FF FF FF FF FF FF FF FF FF E1 E2 E3 E4 FF FF FF FF FF FF E1 E2 E3 E4 FF FF FF FF FF FF
080 FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
090 FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
0A0 FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
0B0 FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
0C0 FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
0D0 FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
0E0 FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
0F0 FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
780 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
790 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
7A0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
7B0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
7C0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
7D0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
7E0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
7F0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
800 01 02 03 04 00 00 00 00 00 00 00 00 00 00 00 00 01 02 03 04 00 00 00 00 00 00 00 00 00 00 00 00
810 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
820 00 00 00 00 00 00 00 00 00 00 00 00 05 06 07 08 00 00 00 00 00 00 00 00 00 05 06 07 08 00 00 00
830 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
840 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
850 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
860 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
870 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

Regards,
VicenÃ.