| From 07e45880bb95fc9c4c45ec91a1503c19b220db3c Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Thu, 20 Feb 2020 13:30:12 +0100 |
| Subject: drm/exynos: dsi: fix workaround for the legacy clock name |
| |
| From: Marek Szyprowski <m.szyprowski@samsung.com> |
| |
| [ Upstream commit c0fd99d659ba5582e09625c7a985d63fc2ca74b5 ] |
| |
| Writing to the built-in strings arrays doesn't work if driver is loaded |
| as kernel module. This is also considered as a bad pattern. Fix this by |
| adding a call to clk_get() with legacy clock name. This fixes following |
| kernel oops if driver is loaded as module: |
| |
| Unable to handle kernel paging request at virtual address bf047978 |
| pgd = (ptrval) |
| [bf047978] *pgd=59344811, *pte=5903c6df, *ppte=5903c65f |
| Internal error: Oops: 80f [#1] SMP ARM |
| Modules linked in: mc exynosdrm(+) analogix_dp rtc_s3c exynos_ppmu i2c_gpio |
| CPU: 1 PID: 212 Comm: systemd-udevd Not tainted 5.6.0-rc2-next-20200219 #326 |
| videodev: Linux video capture interface: v2.00 |
| Hardware name: Samsung Exynos (Flattened Device Tree) |
| PC is at exynos_dsi_probe+0x1f0/0x384 [exynosdrm] |
| LR is at exynos_dsi_probe+0x1dc/0x384 [exynosdrm] |
| ... |
| Process systemd-udevd (pid: 212, stack limit = 0x(ptrval)) |
| ... |
| [<bf03cf14>] (exynos_dsi_probe [exynosdrm]) from [<c09b1ca0>] (platform_drv_probe+0x6c/0xa4) |
| [<c09b1ca0>] (platform_drv_probe) from [<c09afcb8>] (really_probe+0x210/0x350) |
| [<c09afcb8>] (really_probe) from [<c09aff74>] (driver_probe_device+0x60/0x1a0) |
| [<c09aff74>] (driver_probe_device) from [<c09b0254>] (device_driver_attach+0x58/0x60) |
| [<c09b0254>] (device_driver_attach) from [<c09b02dc>] (__driver_attach+0x80/0xbc) |
| [<c09b02dc>] (__driver_attach) from [<c09ade00>] (bus_for_each_dev+0x68/0xb4) |
| [<c09ade00>] (bus_for_each_dev) from [<c09aefd8>] (bus_add_driver+0x130/0x1e8) |
| [<c09aefd8>] (bus_add_driver) from [<c09b0d64>] (driver_register+0x78/0x110) |
| [<c09b0d64>] (driver_register) from [<bf038558>] (exynos_drm_init+0xe8/0x11c [exynosdrm]) |
| [<bf038558>] (exynos_drm_init [exynosdrm]) from [<c0302fa8>] (do_one_initcall+0x50/0x220) |
| [<c0302fa8>] (do_one_initcall) from [<c03dd02c>] (do_init_module+0x60/0x210) |
| [<c03dd02c>] (do_init_module) from [<c03dbf44>] (load_module+0x1c0c/0x2310) |
| [<c03dbf44>] (load_module) from [<c03dc85c>] (sys_finit_module+0xac/0xbc) |
| [<c03dc85c>] (sys_finit_module) from [<c0301000>] (ret_fast_syscall+0x0/0x54) |
| Exception stack(0xd979bfa8 to 0xd979bff0) |
| ... |
| ---[ end trace db16efe05faab470 ]--- |
| |
| Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> |
| Reviewed-by: Andrzej Hajda <a.hajda@samsung.com> |
| Signed-off-by: Inki Dae <inki.dae@samsung.com> |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| drivers/gpu/drm/exynos/exynos_drm_dsi.c | 7 ++++--- |
| 1 file changed, 4 insertions(+), 3 deletions(-) |
| |
| diff --git a/drivers/gpu/drm/exynos/exynos_drm_dsi.c b/drivers/gpu/drm/exynos/exynos_drm_dsi.c |
| index 1ee0b70472fd8..77ff3eed65d62 100644 |
| --- a/drivers/gpu/drm/exynos/exynos_drm_dsi.c |
| +++ b/drivers/gpu/drm/exynos/exynos_drm_dsi.c |
| @@ -1914,9 +1914,10 @@ static int exynos_dsi_probe(struct platform_device *pdev) |
| dsi->clks[i] = devm_clk_get(dev, clk_names[i]); |
| if (IS_ERR(dsi->clks[i])) { |
| if (strcmp(clk_names[i], "sclk_mipi") == 0) { |
| - strcpy(clk_names[i], OLD_SCLK_MIPI_CLK_NAME); |
| - i--; |
| - continue; |
| + dsi->clks[i] = devm_clk_get(dev, |
| + OLD_SCLK_MIPI_CLK_NAME); |
| + if (!IS_ERR(dsi->clks[i])) |
| + continue; |
| } |
| |
| dev_info(dev, "failed to get the clock: %s\n", |
| -- |
| 2.20.1 |
| |