From 63dae7159f232fde3cc04886e880562e87360cf0 Mon Sep 17 00:00:00 2001 From: Kinsey Moore Date: Thu, 15 Sep 2022 15:13:39 -0500 Subject: rtemsbsd/arasan_sd: Prevent disabled device probe 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. --- rtemsbsd/sys/dev/sdhci/arasan_sdhci.c | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) diff --git a/rtemsbsd/sys/dev/sdhci/arasan_sdhci.c b/rtemsbsd/sys/dev/sdhci/arasan_sdhci.c index ccdcb09b..6332260a 100644 --- a/rtemsbsd/sys/dev/sdhci/arasan_sdhci.c +++ b/rtemsbsd/sys/dev/sdhci/arasan_sdhci.c @@ -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); -- cgit v1.2.3