Messages in this thread | | | Date | Mon, 19 Sep 2022 11:43:16 +0200 | Subject | Re: [PATCH 4/4] spi: s3c64xx: Fix large transfers with DMA | From | Krzysztof Kozlowski <> |
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On 16/09/2022 13:39, Vincent Whitchurch wrote: > The COUNT_VALUE in the PACKET_CNT register is 16-bit so the maximum > value is 65535. Asking the driver to transfer a larger size currently > leads to the DMA transfer timing out. Fix this by splitting the > transfer as needed. > > With this, the len>64 KiB tests in spi-loopback-test pass. > > (Note that len==64 KiB tests work even without this patch for some reason. > The driver programs 0 to the COUNT_VALUE field in that case, but it's > unclear if it's by design, since the hardware documentation doesn't say > anything about the behaviour when COUNT_VALUE == 0, so play it safe and > split at 65535.) > > Fixes: 230d42d422e7b69 ("spi: Add s3c64xx SPI Controller driver") > Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Best regards, Krzysztof
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