PatchTrack

From: Heiko Stuebner <heiko@...> Date: Thu, 21 Jan 2016 21:28:21 +0100

Commit-Message

Commit e6d5e7d90be9 ("clk-divider: Fix READ_ONLY when divider > 1") removed the special ops struct for read-only clocks and instead opted to handle them inside the regular ops. On the rk3368 this results in breakage as aclkm now gets set a value. While it is the same divider value, the A53 core still doesn't like it, which can result in the cpu ending up in a hang. The reason being that "ACLKENMasserts one clock cycle before the rising edge of ACLKM" and the clock should only be touched when STANDBYWFIL2 is asserted. To fix this, reintroduce the read-only ops but do include the round_rate callback. That way no writes that may be unsafe are done to the divider register in any case. The Rockchip use of the clk_divider_ops is adapted to this split again, as is the nxp, lpc18xx-ccu driver that was included since the original commit. On lpc18xx-ccu the divider seems to always be read-only so only uses the new ops now. Fixes: e6d5e7d90be9 ("clk-divider: Fix READ_ONLY when divider > 1") Reported-by: Zhang Qing <zhangqing@...> Signed-off-by: Heiko Stuebner <heiko@...>

Patch-Comment

changes in v3: - instead of bailing out of set_rate, reintroduce the _ro_ops with added round_rate callback, as requested by Stephen changes in v2: - emphasize that even setting the same divider may be unsafe drivers/clk/clk-divider.c | 11 ++++++++++- drivers/clk/nxp/clk-lpc18xx-ccu.c | 2 +- drivers/clk/rockchip/clk.c | 4 +++- include/linux/clk-provider.h | 1 + 4 files changed, 15 insertions(+), 3 deletions(-)

Statistics

• 15 lines added
• 3 lines removed

Changes