Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 tests/sdhci-test.c | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/tests/sdhci-test.c b/tests/sdhci-test.c
index f7487808af..0443a23e45 100644
--- a/tests/sdhci-test.c
+++ b/tests/sdhci-test.c
@@ -60,6 +60,13 @@ static uint64_t sdhci_readq(uintptr_t base, uint32_t reg_addr)
     return qtest_readq(qtest, base + reg_addr);
 }
 
+static void sdhci_writeq(uintptr_t base, uint32_t reg_addr, uint64_t value)
+{
+    QTestState *qtest = global_qtest;
+
+    qtest_writeq(qtest, base + reg_addr, value);
+}
+
 static void check_specs_version(uintptr_t addr, uint8_t version)
 {
     uint32_t v;
@@ -78,6 +85,20 @@ static void check_capab_capareg(uintptr_t addr, uint64_t expected_capab)
     g_assert_cmphex(capab, ==, expected_capab);
 }
 
+static void check_capab_readonly(uintptr_t addr)
+{
+    const uint64_t vrand = 0x123456789abcdef;
+    uint64_t capab0, capab1;
+
+    capab0 = sdhci_readq(addr, SDHC_CAPAB);
+    g_assert_cmpuint(capab0, !=, vrand);
+
+    sdhci_writeq(addr, SDHC_CAPAB, vrand);
+    capab1 = sdhci_readq(addr, SDHC_CAPAB);
+    g_assert_cmpuint(capab1, !=, vrand);
+    g_assert_cmpuint(capab1, ==, capab0);
+}
+
 static void test_machine(const void *data)
 {
     const struct sdhci_t *test = data;
@@ -86,6 +107,7 @@ static void test_machine(const void *data)
 
     check_capab_capareg(test->sdhci.addr, test->sdhci.capab.reg);
     check_specs_version(test->sdhci.addr, test->sdhci.version);
+    check_capab_readonly(test->sdhci.addr);
 
     qtest_quit(global_qtest);
 }
-- 
2.15.1