Re: [PATCH v2 0/6] NXP DSPI bugfixes and support for LS1028A

From: Michael Walle
Date: Tue Mar 10 2020 - 04:34:36 EST


Am 2020-03-09 22:07, schrieb Vladimir Oltean:
This series addresses a few issues that were missed during the previous
series "[PATCH 00/12] TCFQ to XSPI migration for NXP DSPI driver", on
SoCs other than LS1021A and LS1043A. DMA mode has been completely broken
by that series, and XSPI mode never worked on little-endian controllers.

Then it introduces support for the LS1028A chip, whose compatible has
recently been documented here:

https://lore.kernel.org/linux-devicetree/20200218171418.18297-1-michael@xxxxxxxx/

The device tree for the LS1028A SoC is extended with DMA channels
definition, such that even though the default operating mode is XSPI,
one can simply change DSPI_XSPI_MODE to DSPI_DMA_MODE in the
devtype_data structure of the driver and use that instead.

For testing, benchmarking and debugging, the mikroBUS connector on the
LS1028A-RDB is made available via spidev.



Let me start with the positive things... something is working, both in
XSPI mode and DMA mode ;) At least the SPI flash is detected.

And please note, that I have my patch applied:
https://lore.kernel.org/lkml/20200310073313.21277-1-michael@xxxxxxxx/

Further note, that the mtd device is either mtd0 in XSPI mode or mtd10
in DMA mode, because the first probe fails due to EPROBE_DEFER.

So starting with XSPI, if you have a big flash and cancel the readout
strange things happen.

# hexdump -C /dev/mtd0
00000000 00 75 68 75 0a ff ff ff ff ff ff ff ff ff ff ff |.uhu............|
00000010 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff |................|
*
^C[ 35.487948] fsl-dspi 2120000.spi: Waiting for transfer to complete failed!
[ 35.495038] spi_master spi2: failed to transfer one message from queue

# hexdump -C /dev/mtd0
00000000 00 75 68 75 0a ff ff ff ff ff ff ff ff ff ff ff |.uhu............|
00000010 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff |................|
*
^C[ 38.495955] fsl-dspi 2120000.spi: Waiting for transfer to complete failed!
[ 38.503097] spi_master spi2: failed to transfer one message from queue
[ 38.509729] Unable to handle kernel paging request at virtual address ffff800095ab3377
[ 38.517676] Mem abort info:
[ 38.520474] ESR = 0x96000045
[ 38.523533] EC = 0x25: DABT (current EL), IL = 32 bits
[ 38.528861] SET = 0, FnV = 0
[ 38.531921] EA = 0, S1PTW = 0
[ 38.535067] Data abort info:
[ 38.537952] ISV = 0, ISS = 0x00000045
[ 38.541797] CM = 0, WnR = 1
[ 38.544771] swapper pgtable: 4k pages, 48-bit VAs, pgdp=0000000082621000
[ 38.551494] [ffff800095ab3377] pgd=00000020fffff003, p4d=00000020fffff003, pud=0000000000000000
[ 38.560229] Internal error: Oops: 96000045 [#1] PREEMPT SMP
[ 38.565819] Modules linked in:
[ 38.568882] CPU: 0 PID: 2729 Comm: hexdump Not tainted 5.6.0-rc4-next-20200306-00052-gd8730cdc8a0b-dirty #193
[ 38.578834] Hardware name: Kontron SMARC-sAL28 (Single PHY) on SMARC Eval 2.0 carrier (DT)
[ 38.587129] pstate: 20000085 (nzCv daIf -PAN -UAO)
[ 38.591941] pc : ktime_get_real_ts64+0x3c/0x110
[ 38.596487] lr : spi_take_timestamp_pre+0x40/0x90
[ 38.601203] sp : ffff800010003d90
[ 38.604525] x29: ffff800010003d90 x28: ffff80001200e000
[ 38.609854] x27: ffff800011da9000 x26: ffff002079c40400
[ 38.615184] x25: ffff8000117fe018 x24: ffff800011daa1a0
[ 38.620513] x23: ffff800015ab3860 x22: ffff800095ab3377
[ 38.625841] x21: 000000000000146e x20: ffff8000120c3000
[ 38.631170] x19: ffff0020795f6e80 x18: ffff800011da9948
[ 38.636498] x17: 0000000000000000 x16: 0000000000000000
[ 38.641826] x15: ffff800095ab3377 x14: 0720072007200720
[ 38.647155] x13: 0720072007200765 x12: 0775076507750771
[ 38.652483] x11: 0720076d076f0772 x10: 0000000000000040
[ 38.657812] x9 : ffff8000108e2100 x8 : ffff800011dcabe8
[ 38.663139] x7 : 0000000000000000 x6 : ffff800015ab3a60
[ 38.668468] x5 : 0000000007200720 x4 : ffff800095ab3377
[ 38.673796] x3 : 0000000000000000 x2 : 0000000000000ab0
[ 38.679125] x1 : ffff800011daa000 x0 : 0000000000000026
[ 38.684454] Call trace:
[ 38.686905] ktime_get_real_ts64+0x3c/0x110
[ 38.691100] spi_take_timestamp_pre+0x40/0x90
[ 38.695470] dspi_fifo_write+0x58/0x2c0
[ 38.699315] dspi_interrupt+0xbc/0xd0
[ 38.702987] __handle_irq_event_percpu+0x78/0x2c0
[ 38.707706] handle_irq_event_percpu+0x3c/0x90
[ 38.712161] handle_irq_event+0x4c/0xd0
[ 38.716008] handle_fasteoi_irq+0xbc/0x170
[ 38.720115] generic_handle_irq+0x2c/0x40
[ 38.724135] __handle_domain_irq+0x68/0xc0
[ 38.728243] gic_handle_irq+0xc8/0x160
[ 38.732000] el1_irq+0xb8/0x180
[ 38.735149] spi_nor_spimem_read_data+0xe0/0x140
[ 38.739779] spi_nor_read+0xc4/0x120
[ 38.743364] mtd_read_oob+0xa8/0xc0
[ 38.746860] mtd_read+0x4c/0x80
[ 38.750007] mtdchar_read+0x108/0x2a0
[ 38.753679] __vfs_read+0x20/0x50
[ 38.757002] vfs_read+0xa4/0x190
[ 38.760237] ksys_read+0x6c/0xf0
[ 38.763471] __arm64_sys_read+0x20/0x30
[ 38.767319] el0_svc_common.constprop.3+0x90/0x160
[ 38.772125] do_el0_svc+0x28/0x90
[ 38.775449] el0_sync_handler+0x118/0x190
[ 38.779468] el0_sync+0x140/0x180
[ 38.782793] Code: 91000294 1400000f d50339bf f9405e80 (f90002c0)
[ 38.788910] ---[ end trace 55da560db4d6bef7 ]---
[ 38.793540] Kernel panic - not syncing: Fatal exception in interrupt
[ 38.799914] SMP: stopping secondary CPUs
[ 38.803849] Kernel Offset: disabled
[ 38.807344] CPU features: 0x10002,20006008
[ 38.811451] Memory Limit: none
[ 38.814513] ---[ end Kernel panic - not syncing: Fatal exception in interrupt ]---



In DMA mode one byte writes seem to work. But at least 5 byte writes do not:

# echo -ne '\x00' > /dev/mtd10
# echo 'huhu' > /dev/mtd10
[ 34.275383] fsl-dspi 2120000.spi: DMA tx timeout
[ 34.280035] fsl-dspi 2120000.spi: DMA transfer failed
[ 34.285116] fsl-dspi 2120000.spi: Waiting for transfer to complete failed!
[ 34.292029] spi_master spi2: failed to transfer one message from queue
sh: write error: Connection timed out
#

Vladimir, what kind of SPI device do you have to test?

-michael




Vladimir Oltean (6):
spi: spi-fsl-dspi: Don't access reserved fields in SPI_MCR
spi: spi-fsl-dspi: Fix little endian access to PUSHR CMD and TXDATA
spi: spi-fsl-dspi: Fix oper_word_size of zero for DMA mode
spi: spi-fsl-dspi: Add support for LS1028A
arm64: dts: ls1028a: Specify the DMA channels for the DSPI controllers
arm64: dts: ls1028a-rdb: Add a spidev node for the mikroBUS

.../boot/dts/freescale/fsl-ls1028a-rdb.dts | 14 ++++++
.../arm64/boot/dts/freescale/fsl-ls1028a.dtsi | 6 +++
drivers/spi/spi-fsl-dspi.c | 50 +++++++++++++++----
3 files changed, 60 insertions(+), 10 deletions(-)