Noralf Trønnes a89bfc5d9a tinydrm/mipi-dbi: Use dma-safe buffers for all SPI transfers ... Buffers passed to spi_sync() must be dma-safe even for tiny buffers since some SPI controllers use DMA for all transfers. Example splat with CONFIG_DMA_API_DEBUG enabled: [ 23.750467] DMA-API: dw_dmac_pci 0000:00:15.0: device driver maps memory from stack [probable addr=000000001e49185d] [ 23.750529] WARNING: CPU: 1 PID: 1296 at kernel/dma/debug.c:1161 check_for_stack+0xb7/0x190 [ 23.750533] Modules linked in: mmc_block(+) spi_pxa2xx_platform(+) pwm_lpss_pci pwm_lpss spi_pxa2xx_pci sdhci_pci cqhci intel_mrfld_pwrbtn extcon_intel_mrfld sdhci intel_mrfld_adc led_class mmc_core ili9341 mipi_dbi tinydrm backlight ti_ads7950 industrialio_triggered_buffer kfifo_buf intel_soc_pmic_mrfld hci_uart btbcm [ 23.750599] CPU: 1 PID: 1296 Comm: modprobe Not tainted 5.0.0-rc7+ #236 [ 23.750605] Hardware name: Intel Corporation Merrifield/BODEGA BAY, BIOS 542 2015.01.21:18.19.48 [ 23.750620] RIP: 0010:check_for_stack+0xb7/0x190 [ 23.750630] Code: 8b 6d 50 4d 85 ed 75 04 4c 8b 6d 10 48 89 ef e8 2f 8b 44 00 48 89 c6 4a 8d 0c 23 4c 89 ea 48 c7 c7 88 d0 82 b4 e8 40 7c f9 ff <0f> 0b 8b 05 79 00 4b 01 85 c0 74 07 5b 5d 41 5c 41 5d c3 8b 05 54 [ 23.750637] RSP: 0000:ffff97bbc0292fa0 EFLAGS: 00010286 [ 23.750646] RAX: 0000000000000000 RBX: ffff97bbc0290000 RCX: 0000000000000006 [ 23.750652] RDX: 0000000000000007 RSI: 0000000000000002 RDI: ffff94b33e115450 [ 23.750658] RBP: ffff94b33c8578b0 R08: 0000000000000002 R09: 00000000000201c0 [ 23.750664] R10: 00000006ecb0ccc6 R11: 0000000000034f38 R12: 000000000000316c [ 23.750670] R13: ffff94b33c84b250 R14: ffff94b33dedd5a0 R15: 0000000000000001 [ 23.750679] FS: 0000000000000000(0000) GS:ffff94b33e100000(0063) knlGS:00000000f7faf690 [ 23.750686] CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 [ 23.750691] CR2: 00000000f7f54faf CR3: 000000000722c000 CR4: 00000000001006e0 [ 23.750696] Call Trace: [ 23.750713] debug_dma_map_sg+0x100/0x340 [ 23.750727] ? dma_direct_map_sg+0x3b/0xb0 [ 23.750739] spi_map_buf+0x25a/0x300 [ 23.750751] __spi_pump_messages+0x2a4/0x680 [ 23.750762] __spi_sync+0x1dd/0x1f0 [ 23.750773] spi_sync+0x26/0x40 [ 23.750790] mipi_dbi_typec3_command_read+0x14d/0x240 [mipi_dbi] [ 23.750802] ? spi_finalize_current_transfer+0x10/0x10 [ 23.750821] mipi_dbi_typec3_command+0x1bc/0x1d0 [mipi_dbi] Reported-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Noralf Trønnes <noralf@tronnes.org> Tested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20190222124329.23046-1-noralf@tronnes.org		2019-03-20 12:02:41 +01:00
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mipi-dbi.h	tinydrm/mipi-dbi: Use dma-safe buffers for all SPI transfers	2019-03-20 12:02:41 +01:00
tinydrm-helpers.h	drm/tinydrm: tinydrm_display_pipe_init() don't use tinydrm_device	2019-02-21 12:20:54 +01:00