spi: spi-qcom-qspi: Use GFP_ATOMIC flag while allocating for descriptor

While allocating for DMA descriptor, GFP_KERNEL flag is being used and
this allocation happens within critical section with spinlock acquired.
This generates a static checker warning.

Use GFP_ATOMIC to prevent sleeping; and since this increases chances of
allocation failure, add handling accordingly.

Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/all/abc223e8-44af-40bb-a0bd-9865b393f435@moroto.mountain/
Signed-off-by: Vijaya Krishna Nivarthi <quic_vnivarth@quicinc.com>
Fixes: b5762d95607e ("spi: spi-qcom-qspi: Add DMA mode support")
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/1690285689-30233-3-git-send-email-quic_vnivarth@quicinc.com
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/drivers/spi/spi-qcom-qspi.c b/drivers/spi/spi-qcom-qspi.c
index 21a1360..67c1017 100644 (file)
--- a/drivers/spi/spi-qcom-qspi.c
+++ b/drivers/spi/spi-qcom-qspi.c
@@ -308,9 +308,11 @@ static int qcom_qspi_alloc_desc(struct qcom_qspi *ctrl, dma_addr_t dma_ptr,
        dma_addr_t dma_cmd_desc;
 
        /* allocate for dma cmd descriptor */
-       virt_cmd_desc = dma_pool_alloc(ctrl->dma_cmd_pool, GFP_KERNEL | __GFP_ZERO, &dma_cmd_desc);
-       if (!virt_cmd_desc)
-               return -ENOMEM;
+       virt_cmd_desc = dma_pool_alloc(ctrl->dma_cmd_pool, GFP_ATOMIC | __GFP_ZERO, &dma_cmd_desc);
+       if (!virt_cmd_desc) {
+               dev_warn_once(ctrl->dev, "Couldn't find memory for descriptor\n");
+               return -EAGAIN;
+       }
 
        ctrl->virt_cmd_desc[ctrl->n_cmd_desc] = virt_cmd_desc;
        ctrl->dma_cmd_desc[ctrl->n_cmd_desc] = dma_cmd_desc;