Messages in this thread Patch in this message | | | From | Arnd Bergmann <> | Subject | [PATCH] mic: avoid statically declaring a 'struct device'. | Date | Wed, 10 Jul 2019 15:06:51 +0200 |
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Generally, declaring a platform device as a static variable is a bad idea and can cause all kinds of problems, in particular with the DMA configuration and lifetime rules.
A specific problem we hit here is from a bug in clang that warns about certain (otherwise valid) macros when used in static variables:
drivers/misc/mic/card/mic_x100.c:285:27: warning: shift count >= width of type [-Wshift-count-overflow] static u64 mic_dma_mask = DMA_BIT_MASK(64); ^~~~~~~~~~~~~~~~ include/linux/dma-mapping.h:141:54: note: expanded from macro 'DMA_BIT_MASK' #define DMA_BIT_MASK(n) (((n) == 64) ? ~0ULL : ((1ULL<<(n))-1)) ^ ~~~
A slightly better way here is to create the platform device from a platform_device_info. This avoids the warning and some other problems, but is still not ideal because the device creation should really be separated from the driver.
Fixes: dd8d8d44df64 ("misc: mic: MIC card driver specific changes to enable SCIF") Signed-off-by: Arnd Bergmann <arnd@arndb.de> --- drivers/misc/mic/card/mic_x100.c | 24 ++++++++++-------------- 1 file changed, 10 insertions(+), 14 deletions(-)
diff --git a/drivers/misc/mic/card/mic_x100.c b/drivers/misc/mic/card/mic_x100.c index 266ffb6f6c44..a5821166f943 100644 --- a/drivers/misc/mic/card/mic_x100.c +++ b/drivers/misc/mic/card/mic_x100.c @@ -282,18 +282,6 @@ static void mic_platform_shutdown(struct platform_device *pdev) mic_remove(pdev); } -static u64 mic_dma_mask = DMA_BIT_MASK(64); - -static struct platform_device mic_platform_dev = { - .name = mic_driver_name, - .id = 0, - .num_resources = 0, - .dev = { - .dma_mask = &mic_dma_mask, - .coherent_dma_mask = DMA_BIT_MASK(64), - }, -}; - static struct platform_driver __refdata mic_platform_driver = { .probe = mic_probe, .remove = mic_remove, @@ -307,6 +295,12 @@ static int __init mic_init(void) { int ret; struct cpuinfo_x86 *c = &cpu_data(0); + struct platform_device_info mic_platform_info = { + .name = mic_driver_name, + .dma_mask = DMA_BIT_MASK(64), + }; + struct platform_device *pdev; + if (!(c->x86 == 11 && c->x86_model == 1)) { ret = -ENODEV; @@ -316,9 +310,11 @@ static int __init mic_init(void) request_module("mic_x100_dma"); mic_init_card_debugfs(); - ret = platform_device_register(&mic_platform_dev); + + pdev = platform_device_register_full(&mic_platform_info); + ret = PTR_ERR_OR_ZERO(pdev); if (ret) { - pr_err("platform_device_register ret %d\n", ret); + pr_err("platform_device_register_full ret %d\n", ret); goto cleanup_debugfs; } ret = platform_driver_register(&mic_platform_driver); -- 2.20.0
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