From: Douglas Anderson <dianders@chromium.org>
To: Andy Gross <agross@kernel.org>,
Bjorn Andersson <bjorn.andersson@linaro.org>,
Maulik Shah <mkshah@codeaurora.org>
Cc: mka@chromium.org, Rajendra Nayak <rnayak@codeaurora.org>,
evgreen@chromium.org, Lina Iyer <ilina@codeaurora.org>,
swboyd@chromium.org, Douglas Anderson <dianders@chromium.org>,
linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [RFT PATCH v2 06/10] drivers: qcom: rpmh-rsc: Comment tcs_is_free() + warn if state mismatch
Date: Wed, 11 Mar 2020 16:13:44 -0700 [thread overview]
Message-ID: <20200311161104.RFT.v2.6.Icf2213131ea652087f100129359052c83601f8b0@changeid> (raw)
In-Reply-To: <20200311231348.129254-1-dianders@chromium.org>
tcs_is_free() had two checks in it: does the software think that the
TCS is free and does the hardware think that the TCS is free. Let's
comment this and also add a warning in the case that software and
hardware disagree, at least for ACTIVE_ONLY TCS.
Signed-off-by: Douglas Anderson <dianders@chromium.org>
---
Changes in v2:
- Comment tcs_is_free() new for v2; replaces old patch 6.
drivers/soc/qcom/rpmh-rsc.c | 23 +++++++++++++++++++++--
1 file changed, 21 insertions(+), 2 deletions(-)
diff --git a/drivers/soc/qcom/rpmh-rsc.c b/drivers/soc/qcom/rpmh-rsc.c
index 9d2669cbd994..93f5d1fb71ca 100644
--- a/drivers/soc/qcom/rpmh-rsc.c
+++ b/drivers/soc/qcom/rpmh-rsc.c
@@ -181,8 +181,27 @@ static void write_tcs_reg_sync(struct rsc_drv *drv, int reg, int tcs_id,
*/
static bool tcs_is_free(struct rsc_drv *drv, int tcs_id)
{
- return !test_bit(tcs_id, drv->tcs_in_use) &&
- read_tcs_reg(drv, RSC_DRV_STATUS, tcs_id);
+ /* If software thinks it's in use then it's definitely in use */
+ if (test_bit(tcs_id, drv->tcs_in_use))
+ return false;
+
+ /* If hardware agrees it's free then it's definitely free */
+ if (read_tcs_reg(drv, RSC_DRV_STATUS, tcs_id) != 0)
+ return true;
+
+ /*
+ * If we're here then software and hardware disagree about whether
+ * the TCS is free. Software thinks it is free and hardware thinks
+ * it is not.
+ *
+ * Maybe this should be a warning in all cases, but it's almost
+ * certainly a warning for the ACTIVE_TCS where nobody else should
+ * be doing anything else behind our backs. For now we'll just
+ * warn there and then still return that we're in use.
+ */
+ WARN(drv->tcs[tcs_id].type == ACTIVE_TCS,
+ "Driver thought TCS was free but HW reported busy\n");
+ return false;
}
/**
--
2.25.1.481.gfbce0eb801-goog
next prev parent reply other threads:[~2020-03-11 23:14 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-11 23:13 [RFT PATCH v2 00/10] drivers: qcom: rpmh-rsc: Cleanup / add lots of comments Douglas Anderson
2020-03-11 23:13 ` [RFT PATCH v2 01/10] drivers: qcom: rpmh-rsc: Clean code reading/writing regs/cmds Douglas Anderson
2020-04-01 8:12 ` Maulik Shah
2020-03-11 23:13 ` [RFT PATCH v2 02/10] drivers: qcom: rpmh-rsc: Document the register layout better Douglas Anderson
2020-04-01 8:14 ` Maulik Shah
2020-04-02 20:15 ` Doug Anderson
2020-03-11 23:13 ` [RFT PATCH v2 03/10] drivers: qcom: rpmh-rsc: Fold tcs_ctrl_write() into its single caller Douglas Anderson
2020-04-01 8:17 ` Maulik Shah
2020-03-11 23:13 ` [RFT PATCH v2 04/10] drivers: qcom: rpmh-rsc: Remove get_tcs_of_type() abstraction Douglas Anderson
2020-04-01 8:18 ` Maulik Shah
2020-03-11 23:13 ` [RFT PATCH v2 05/10] drivers: qcom: rpmh-rsc: A lot of comments Douglas Anderson
2020-04-01 11:29 ` Maulik Shah
2020-04-02 20:18 ` Doug Anderson
2020-04-08 11:10 ` Maulik Shah
2020-03-11 23:13 ` Douglas Anderson [this message]
2020-04-01 11:38 ` [RFT PATCH v2 06/10] drivers: qcom: rpmh-rsc: Comment tcs_is_free() + warn if state mismatch Maulik Shah
2020-04-02 20:19 ` Doug Anderson
2020-03-11 23:13 ` [RFT PATCH v2 07/10] drivers: qcom: rpmh-rsc: Warning if tcs_write() used for non-active Douglas Anderson
2020-04-01 12:40 ` Maulik Shah
2020-04-02 20:19 ` Doug Anderson
2020-03-11 23:13 ` [RFT PATCH v2 08/10] drivers: qcom: rpmh-rsc: spin_lock_irqsave() for tcs_invalidate() Douglas Anderson
2020-03-26 21:44 ` Doug Anderson
2020-03-11 23:13 ` [RFT PATCH v2 09/10] drivers: qcom: rpmh-rsc: Kill cmd_cache and find_match() with fire Douglas Anderson
2020-03-11 23:13 ` [RFT PATCH v2 10/10] drivers: qcom: rpmh-rsc: Always use -EAGAIN, never -EBUSY Douglas Anderson
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