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From:   Linus Walleij <linus.walleij@linaro.org>
Date:   Tue, 10 Jan 2023 20:19:15 +0100
Subject: [PATCH v2 4/6] crypto: stm32/hash: Wait for idle before final CPU xmit
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Message-Id: <20221227-ux500-stm32-hash-v2-4-bc443bc44ca4@linaro.org>
References: <20221227-ux500-stm32-hash-v2-0-bc443bc44ca4@linaro.org>
In-Reply-To: <20221227-ux500-stm32-hash-v2-0-bc443bc44ca4@linaro.org>
To:     Herbert Xu <herbert@gondor.apana.org.au>,
        "David S. Miller" <davem@davemloft.net>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Maxime Coquelin <mcoquelin.stm32@gmail.com>,
        Alexandre Torgue <alexandre.torgue@foss.st.com>,
        Lionel Debieve <lionel.debieve@foss.st.com>
Cc:     linux-crypto@vger.kernel.org, devicetree@vger.kernel.org,
        linux-stm32@st-md-mailman.stormreply.com,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        Linus Walleij <linus.walleij@linaro.org>
Precedence: bulk

When calculating the hash using the CPU, right before the final
hash calculation, heavy testing on Ux500 reveals that it is wise
to wait for the hardware to go idle before calculating the
final hash.

The default test vectors mostly worked fine, but when I used the
extensive tests and stress the hardware I ran into this problem.

Acked-by: Lionel Debieve <lionel.debieve@foss.st.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
ChangeLog v1->v2:
- Pick up Lionel's ACK
---
 drivers/crypto/stm32/stm32-hash.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/crypto/stm32/stm32-hash.c b/drivers/crypto/stm32/stm32-hash.c
index cc0a4e413a82..d4eefd8292ff 100644
--- a/drivers/crypto/stm32/stm32-hash.c
+++ b/drivers/crypto/stm32/stm32-hash.c
@@ -362,6 +362,9 @@ static int stm32_hash_xmit_cpu(struct stm32_hash_dev *hdev,
 		stm32_hash_write(hdev, HASH_DIN, buffer[count]);
 
 	if (final) {
+		if (stm32_hash_wait_busy(hdev))
+			return -ETIMEDOUT;
+
 		stm32_hash_set_nblw(hdev, length);
 		reg = stm32_hash_read(hdev, HASH_STR);
 		reg |= HASH_STR_DCAL;

-- 
2.39.0