Messages in this thread Patch in this message |  | | From | Viken Dadhaniya <> | | Date | Fri, 29 May 2026 00:33:08 +0530 | | Subject | [PATCH v1] spi: qcom-geni: Fix cs_change handling on the last transfer |
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Commit b99181cdf9fa ("spi-geni-qcom: remove manual CS control") introduced automatic CS control via the FRAGMENTATION bit, but missed the case where cs_change is set on the last transfer in a message.
For the last transfer, cs_change means that CS should remain asserted after the message completes. Since GENI SPI controls CS through FRAGMENTATION, set FRAGMENTATION for this case as well as for non-last transfers where cs_change is not set.
Additionally, setup_gsi_xfer() was storing FRAGMENTATION (BIT(2) = 4) in peripheral.fragmentation, which is a boolean field consumed by gpi_create_spi_tre() via u32_encode_bits(..., TRE_SPI_GO_FRAG). Storing 4 causes u32_encode_bits to mask it to 0, silently disabling the FRAG bit in the GPI TRE regardless of the cs_change logic. Store 1 instead.
Without these fixes, TPM TIS SPI transfers deassert CS between single-transfer messages that use cs_change to keep CS asserted across the header, wait-state, and data phases, breaking TCG SPI flow control:
tpm_tis_spi: probe of spi11.0 failed with error -110
Update both setup_se_xfer() and setup_gsi_xfer() to handle this condition.
Fixes: b99181cdf9fa ("spi-geni-qcom: remove manual CS control") Cc: stable@vger.kernel.org Signed-off-by: Viken Dadhaniya <viken.dadhaniya@oss.qualcomm.com> --- drivers/spi/spi-geni-qcom.c | 27 +++++++++++++++++++-------- 1 file changed, 19 insertions(+), 8 deletions(-)
diff --git a/drivers/spi/spi-geni-qcom.c b/drivers/spi/spi-geni-qcom.c index a04cdc1e5ad4..0618f6bd7878 100644 --- a/drivers/spi/spi-geni-qcom.c +++ b/drivers/spi/spi-geni-qcom.c @@ -449,10 +449,15 @@ static int setup_gsi_xfer(struct spi_transfer *xfer, struct spi_geni_master *mas return ret; } - if (!xfer->cs_change) { - if (!list_is_last(&xfer->transfer_list, &spi->cur_msg->transfers)) - peripheral.fragmentation = FRAGMENTATION; - } + /* + * Set fragmentation to keep CS asserted after this transfer when: + * - non-last transfer with cs_change=0: keep CS between chained transfers + * - last transfer with cs_change=1: keep CS asserted after the message + * (e.g. TPM TIS SPI uses cs_change=1 on single-transfer messages to + * keep CS asserted across header, wait-state and data phases) + */ + peripheral.fragmentation = list_is_last(&xfer->transfer_list, &spi->cur_msg->transfers) ? + xfer->cs_change : !xfer->cs_change; if (peripheral.cmd & SPI_RX) { dmaengine_slave_config(mas->rx, &config); @@ -858,10 +863,16 @@ static int setup_se_xfer(struct spi_transfer *xfer, mas->cur_xfer_mode = GENI_SE_DMA; geni_se_select_mode(se, mas->cur_xfer_mode); - if (!xfer->cs_change) { - if (!list_is_last(&xfer->transfer_list, &spi->cur_msg->transfers)) - m_params = FRAGMENTATION; - } + /* + * Set FRAGMENTATION to keep CS asserted after this transfer when: + * - non-last transfer with cs_change=0: keep CS between chained transfers + * - last transfer with cs_change=1: keep CS asserted after the message + * (e.g. TPM TIS SPI uses cs_change=1 on single-transfer messages to + * keep CS asserted across header, wait-state and data phases) + */ + if (list_is_last(&xfer->transfer_list, &spi->cur_msg->transfers) ? + xfer->cs_change : !xfer->cs_change) + m_params = FRAGMENTATION; /* * Lock around right before we start the transfer since our --- base-commit: e7d700e14934e68f86338c5610cf2ae76798b663 change-id: 20260528-fix-spi-fragmentation-bit-logic-880394337ff9 Best regards, -- Viken Dadhaniya <viken.dadhaniya@oss.qualcomm.com>
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