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rtemsbsd/arasan_sd: Prevent disabled device probe

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Probing a SDIO/SDHCI interface that has been disabled by system init via
holding it in reset can cause a CPU hang. This prevents probing of
devices that have been disabled in such a manner on ZynqMP systems.
This commit is contained in:
Kinsey Moore 2022-09-15 15:13:39 -05:00 committed by Joel Sherrill
parent a0d36f58fd
commit 63dae7159f
1 changed files with 25 additions and 0 deletions
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25
rtemsbsd/sys/dev/sdhci/arasan_sdhci.c
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@ -246,6 +246,31 @@ arasan_sdhci_attach(device_t dev)
goto fail;
}
/*
* These devices may be disabled by being held in reset. If this is the
* case, a read attempt in its register range will result in a CPU hang.
* Detect this situation and avoid probing the device in this situation.
*/
#if defined(LIBBSP_AARCH64_XILINX_ZYNQMP_BSP_H)
volatile uint32_t *RST_LPD_IOU2_ptr = (uint32_t*)0xFF5E0238;
uint32_t RST_LPD_IOU2 = *RST_LPD_IOU2_ptr;
uint32_t SDIO0_disabled = RST_LPD_IOU2 & (1 << 5);
uint32_t SDIO1_disabled = RST_LPD_IOU2 & (1 << 6);
if ( sc->mem_res == 0xFF160000 ) {
if ( SDIO0_disabled != 0 ) {
device_printf(dev, "SDIO0 disabled\n");
err = ENXIO;
goto fail;
}
} else {
if ( SDIO1_disabled != 0 ) {
device_printf(dev, "SDIO1 disabled\n");
err = ENXIO;
goto fail;
}
}
#endif
rid = 0;
sc->irq_res = bus_alloc_resource_any(dev, SYS_RES_IRQ, &rid,
RF_ACTIVE);