Hi Doug, On 2018-10-12 04:21, Doug Anderson wrote:
Hi, On Thu, Oct 11, 2018 at 5:33 AM Can Guo <cang@xxxxxxxxxxxxxx> wrote:static int ufs_qcom_host_clk_get(struct device *dev, - const char *name, struct clk **clk_out) + const char *name, struct clk **clk_out, bool optional) { struct clk *clk; int err = 0; clk = devm_clk_get(dev, name); - if (IS_ERR(clk)) { + if (clk == ERR_PTR(-EPROBE_DEFER)) { + err = -EPROBE_DEFER;+ dev_warn(dev, "required clock %s hasn't probed yet, err %d\n",+ name, err); + } else if (IS_ERR(clk)) { + if (optional) + return 0;Change this function to: static int ufs_qcom_host_clk_get(struct device *dev, const char *name, struct clk **clk_out, bool optional) { struct clk *clk; int err; clk = devm_clk_get(dev, name); if (!IS_ERR(clk)) { *clk_out = clk; return 0; } err = PTR_ERR(clk); if (optional && err == -ENOENT) { *clk_out = NULL; return 0; } if (err != -EPROBE_DEFER) dev_err(dev, "failed to get %s err %d", name, err); return err; } Specifically: * Typically it just spams the log to print something when you see an -EPROBE_DEFER. * If a clock is optional you should only consider things a success only if "-ENOENT" was returned. All other errors should be considered fatal. * If a clock is optional it's slightly cleaner to set *clk_out to NULL. I know you're initting global data that happened to already be NULL by default, but it still feels nice for the abstraction of the function to do this. * Please don't pass __func__ to your error messages.
Thank you for the detailed instructions. Shall make the change like so.
err = PTR_ERR(clk); dev_err(dev, "%s: failed to get %s err %d", __func__, name, err);@@ -113,10 +119,10 @@ static void ufs_qcom_disable_lane_clks(struct ufs_qcom_host *host)if (!host->is_lane_clks_enabled) return; - if (host->hba->lanes_per_direction > 1) + if (host->tx_l1_sync_clk)Remove this "if". Always call clk_disable_unprepare() which will be a no-op if "host->tx_l1_sync_clk" is NULL. clk_disable_unprepare() is a no-op for NULL clocks by design specifically to make code like this cleaner.
Shall do.
clk_disable_unprepare(host->tx_l1_sync_clk); clk_disable_unprepare(host->tx_l0_sync_clk); - if (host->hba->lanes_per_direction > 1) + if (host->rx_l1_sync_clk)Remove this "if". Always call clk_disable_unprepare() which will be a no-op if "host->rx_l1_sync_clk" is NULL. clk_disable_unprepare() is a no-op for NULL clocks by design specifically to make code like this cleaner.
Shall do.
clk_disable_unprepare(host->rx_l1_sync_clk); clk_disable_unprepare(host->rx_l0_sync_clk);@@ -141,12 +147,14 @@ static int ufs_qcom_enable_lane_clks(struct ufs_qcom_host *host)if (err) goto disable_rx_l0; - if (host->hba->lanes_per_direction > 1) { + if (host->rx_l1_sync_clk) {Remove this "if". Always call ufs_qcom_host_clk_enable(). The clk_prepare_enable() inside ufs_qcom_host_clk_enable() will be a no-op if "host->rx_l1_sync_clk" is NULL and will return 0 (no error).
Shall do so.
err = ufs_qcom_host_clk_enable(dev, "rx_lane1_sync_clk",host->rx_l1_sync_clk); if (err) goto disable_tx_l0; + } + if (host->tx_l1_sync_clk) {Remove this "if". Always call ufs_qcom_host_clk_enable(). The clk_prepare_enable() inside ufs_qcom_host_clk_enable() will be a no-op if "host->tx_l1_sync_clk" is NULL and will return 0 (no error). -Doug
Shall do so. Thank you. -Can Guo
