From b1b3f0622a9d52ac19a63619911823c89a4d85a4 Mon Sep 17 00:00:00 2001 From: Jerome Brunet Date: Fri, 13 Dec 2019 11:33:04 +0100 Subject: [PATCH 1/2] clk: meson: g12a: fix missing uart2 in regmap table UART2 peripheral is missing from the regmap fixup table of the g12a family clock controller. As it is, any access to this clock would Oops, which is not great. Add the clock to the table to fix the problem. Fixes: 085a4ea93d54 ("clk: meson: g12a: add peripheral clock controller") Reported-by: Dmitry Shmidt Tested-by: Dmitry Shmidt Acked-by: Neil Armstrong Tested-by: Kevin Hilman Signed-off-by: Jerome Brunet --- drivers/clk/meson/g12a.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/clk/meson/g12a.c b/drivers/clk/meson/g12a.c index b3af61cc6fb9..d2760a021301 100644 --- a/drivers/clk/meson/g12a.c +++ b/drivers/clk/meson/g12a.c @@ -4692,6 +4692,7 @@ static struct clk_regmap *const g12a_clk_regmaps[] = { &g12a_bt656, &g12a_usb1_to_ddr, &g12a_mmc_pclk, + &g12a_uart2, &g12a_vpu_intr, &g12a_gic, &g12a_sd_emmc_a_clk0, From d8488a41800d9f5c80bc0d17b9cc2c91b4841464 Mon Sep 17 00:00:00 2001 From: Remi Pommarel Date: Sun, 15 Dec 2019 12:47:05 +0100 Subject: [PATCH 2/2] clk: meson: pll: Fix by 0 division in __pll_params_to_rate() Some meson pll registers can be initialized with 0 as N value, introducing the following division by 0 when computing rate : UBSAN: Undefined behaviour in drivers/clk/meson/clk-pll.c:75:9 division by zero CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.4.0-rc3-608075-g86c9af8630e1-dirty #400 Call trace: dump_backtrace+0x0/0x1c0 show_stack+0x14/0x20 dump_stack+0xc4/0x100 ubsan_epilogue+0x14/0x68 __ubsan_handle_divrem_overflow+0x98/0xb8 __pll_params_to_rate+0xdc/0x140 meson_clk_pll_recalc_rate+0x278/0x3a0 __clk_register+0x7c8/0xbb0 devm_clk_hw_register+0x54/0xc0 meson_eeclkc_probe+0xf4/0x1a0 platform_drv_probe+0x54/0xd8 really_probe+0x16c/0x438 driver_probe_device+0xb0/0xf0 device_driver_attach+0x94/0xa0 __driver_attach+0x70/0x108 bus_for_each_dev+0xd8/0x128 driver_attach+0x30/0x40 bus_add_driver+0x1b0/0x2d8 driver_register+0xbc/0x1d0 __platform_driver_register+0x78/0x88 axg_driver_init+0x18/0x20 do_one_initcall+0xc8/0x24c kernel_init_freeable+0x2b0/0x344 kernel_init+0x10/0x128 ret_from_fork+0x10/0x18 This checks if N is null before doing the division. Fixes: 7a29a869434e ("clk: meson: Add support for Meson clock controller") Reviewed-by: Martin Blumenstingl Signed-off-by: Remi Pommarel [jbrunet@baylibre.com: update the comment in above the fix] Signed-off-by: Jerome Brunet --- drivers/clk/meson/clk-pll.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/clk/meson/clk-pll.c b/drivers/clk/meson/clk-pll.c index ddb1e5634739..3a5853ca98c6 100644 --- a/drivers/clk/meson/clk-pll.c +++ b/drivers/clk/meson/clk-pll.c @@ -77,6 +77,15 @@ static unsigned long meson_clk_pll_recalc_rate(struct clk_hw *hw, unsigned int m, n, frac; n = meson_parm_read(clk->map, &pll->n); + + /* + * On some HW, N is set to zero on init. This value is invalid as + * it would result in a division by zero. The rate can't be + * calculated in this case + */ + if (n == 0) + return 0; + m = meson_parm_read(clk->map, &pll->m); frac = MESON_PARM_APPLICABLE(&pll->frac) ?