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drivers: espi: xec: Avoid flash interrupt by ROM bootloader activity

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When MEC15xx boots in MAFS, ROM bootloader performs activity over
eSPI flash channel prior to FW is loaded.
Need to clear STS_DONE during early eSPI driver initialization,
before enabling interrupts to avoid unexpected ISRs in FW.

Otherwise this would cause flash_lock semaphore to be incremented
due to ROM activity and result in FW's first espi flash request
to return immediately even before eSPI bus transaction completes.

Signed-off-by: Jose Alberto Meza <jose.a.meza.arellano@intel.com>
This commit is contained in:
Jose Alberto Meza 2020-11-09 10:43:48 -08:00 • committed by Andrew Boie
commit df43f17883
1 changed files with 4 additions and 0 deletions
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4
drivers/espi/espi_mchp_xec.c
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@ -710,6 +710,10 @@ static void espi_init_flash(const struct device *dev)
LOG_DBG("%s", __func__);
/* Need to clear status done when ROM boots in MAF */
LOG_DBG("%s ESPI_FC_REGS->CFG %X", __func__, ESPI_FC_REGS->CFG);
ESPI_FC_REGS->STS = MCHP_ESPI_FC_STS_DONE;
/* Enable interrupts */
MCHP_GIRQ_ENSET(config->bus_girq_id) = BIT(MCHP_ESPI_FC_GIRQ_POS);
ESPI_FC_REGS->IEN |= MCHP_ESPI_FC_IEN_CHG_EN;