From: Chen-Yu Tsai wenst@chromium.org
commit e46ceea3148163166ef9b7bcac578e72dd30c064 upstream.
Clocks are properly reference counted and do not need to be inside the lock range.
Right now this triggers a false-positive lockdep warning on MT8192 based Chromebooks, through a combination of mtk-scp that has a cros-ec-rpmsg sub-device, the (actual) cros-ec I2C adapter registration, I2C client (not on cros-ec) probe doing i2c transfers and enabling clocks.
This is a false positive because the cros-ec-rpmsg under mtk-scp does not have an I2C adapter, and also each I2C adapter and cros-ec instance have their own mutex.
Move the clk operations outside of the send_lock range.
Fixes: 63c13d61eafe ("remoteproc/mediatek: add SCP support for mt8183") Signed-off-by: Chen-Yu Tsai wenst@chromium.org Reviewed-by: AngeloGioacchino Del Regno angelogioacchino.delregno@collabora.com Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20230104083110.736377-1-wenst@chromium.org [Fixed "Fixes:" tag line] Signed-off-by: Mathieu Poirier mathieu.poirier@linaro.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/remoteproc/mtk_scp_ipi.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-)
--- a/drivers/remoteproc/mtk_scp_ipi.c +++ b/drivers/remoteproc/mtk_scp_ipi.c @@ -164,21 +164,21 @@ int scp_ipi_send(struct mtk_scp *scp, u3 WARN_ON(len > sizeof(send_obj->share_buf)) || WARN_ON(!buf)) return -EINVAL;
- mutex_lock(&scp->send_lock); - ret = clk_prepare_enable(scp->clk); if (ret) { dev_err(scp->dev, "failed to enable clock\n"); - goto unlock_mutex; + return ret; }
+ mutex_lock(&scp->send_lock); + /* Wait until SCP receives the last command */ timeout = jiffies + msecs_to_jiffies(2000); do { if (time_after(jiffies, timeout)) { dev_err(scp->dev, "%s: IPI timeout!\n", __func__); ret = -ETIMEDOUT; - goto clock_disable; + goto unlock_mutex; } } while (readl(scp->reg_base + scp->data->host_to_scp_reg));
@@ -205,10 +205,9 @@ int scp_ipi_send(struct mtk_scp *scp, u3 ret = 0; }
-clock_disable: - clk_disable_unprepare(scp->clk); unlock_mutex: mutex_unlock(&scp->send_lock); + clk_disable_unprepare(scp->clk);
return ret; }