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

Vicente Bergas <vicencb@xxxxxxxxx> · Sat, 06 Apr 2019 19:34:32 +0200

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,
 Vicenç.