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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, Lina Iyer <ilina@codeaurora.org>,
	Rajendra Nayak <rnayak@codeaurora.org>,
	swboyd@chromium.org, evgreen@chromium.org,
	Douglas Anderson <dianders@chromium.org>,
	linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH v3 07/10] drivers: qcom: rpmh-rsc: tcs_is_free() can just check tcs_in_use
Date: Tue,  7 Apr 2020 16:50:21 -0700	[thread overview]
Message-ID: <20200407164915.v3.7.Icf2213131ea652087f100129359052c83601f8b0@changeid> (raw)
In-Reply-To: <20200407235024.260460-1-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.  I
couldn't figure out in which case the hardware could think that a TCS
was in-use but software thought it was free.  Apparently there is no
case and the extra check can be removed.  This apparently has already
been done in a downstream patch.

Suggested-by: Maulik Shah <mkshah@codeaurora.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
---

Changes in v3:
- Replace ("...warn if state mismatch") w/ ("...just check tcs_in_use")

Changes in v2:
- Comment tcs_is_free() new for v2; replaces old patch 6.

 drivers/soc/qcom/rpmh-rsc.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/soc/qcom/rpmh-rsc.c b/drivers/soc/qcom/rpmh-rsc.c
index 84ae3e514eee..9502e7ea96be 100644
--- a/drivers/soc/qcom/rpmh-rsc.c
+++ b/drivers/soc/qcom/rpmh-rsc.c
@@ -177,7 +177,6 @@ static void write_tcs_reg_sync(struct rsc_drv *drv, int reg, int tcs_id,
  * @tcs_id: The global ID of this TCS.
  *
  * Returns true if nobody has claimed this TCS (by setting tcs_in_use).
- * If the TCS looks free, checks that the hardware agrees.
  *
  * Must be called with the drv->lock held or the tcs_lock for the TCS being
  * tested. If only the tcs_lock is held then it is possible that this
@@ -188,8 +187,7 @@ 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);
+	return !test_bit(tcs_id, drv->tcs_in_use);
 }
 
 /**
-- 
2.26.0.292.g33ef6b2f38-goog


  parent reply	other threads:[~2020-04-07 23:51 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-04-07 23:50 [PATCH v3 00/10] drivers: qcom: rpmh-rsc: Cleanup / add lots of comments Douglas Anderson
2020-04-07 23:50 ` [PATCH v3 01/10] drivers: qcom: rpmh-rsc: Clean code reading/writing TCS regs/cmds Douglas Anderson
2020-04-07 23:50 ` [PATCH v3 02/10] drivers: qcom: rpmh-rsc: Document the register layout better Douglas Anderson
2020-04-08 10:59   ` Maulik Shah
2020-04-07 23:50 ` [PATCH v3 03/10] drivers: qcom: rpmh-rsc: Fold tcs_ctrl_write() into its single caller Douglas Anderson
2020-04-07 23:50 ` [PATCH v3 04/10] drivers: qcom: rpmh-rsc: Remove get_tcs_of_type() abstraction Douglas Anderson
2020-04-07 23:50 ` [PATCH v3 05/10] drivers: qcom: rpmh-rsc: Kill cmd_cache and find_match() with fire Douglas Anderson
2020-04-08 11:11   ` Maulik Shah
2020-04-07 23:50 ` [PATCH v3 06/10] drivers: qcom: rpmh-rsc: A lot of comments Douglas Anderson
2020-04-08 11:25   ` Maulik Shah
2020-04-07 23:50 ` Douglas Anderson [this message]
2020-04-08 11:25   ` [PATCH v3 07/10] drivers: qcom: rpmh-rsc: tcs_is_free() can just check tcs_in_use Maulik Shah
2020-04-07 23:50 ` [PATCH v3 08/10] drivers: qcom: rpmh-rsc: Don't double-check rpmh Douglas Anderson
2020-04-08 12:23   ` Maulik Shah
2020-04-09  0:10     ` Doug Anderson
2020-04-07 23:50 ` [PATCH v3 09/10] drivers: qcom: rpmh-rsc: Caller handles tcs_invalidate() exclusivity Douglas Anderson
2020-04-08 13:29   ` Maulik Shah
2020-04-07 23:50 ` [PATCH v3 10/10] drivers: qcom: rpmh-rsc: read_tcs_reg()/write_tcs_reg() are not for IRQ Douglas Anderson
2020-04-08 13:32   ` Maulik Shah

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