From: Tony Lindgren tony@atomide.com
[ Upstream commit 7078a5ba7a58e5db07583b176f8a03e0b8714731 ]
We have rst_map_012 used for various accelerators like dsp, ipu and iva. For these use cases, we have rstctrl bit 2 control the subsystem module reset, and have and bits 0 and 1 control the accelerator specific features.
If the bootloader, or kexec boot, has left any accelerator specific reset bits deasserted, deasserting bit 2 reset will potentially enable an accelerator with unconfigured MMU and no firmware. And we may get spammed with a lot by warnings on boot with "Data Access in User mode during Functional access", or depending on the accelerator, the system can also just hang.
This issue can be quite easily reproduced by setting a rst_map_012 type rstctrl register to 0 or 4 in the bootloader, and booting the system.
Let's just assert all reset bits for rst_map_012 type resets. So far it looks like the other rstctrl types don't need this. If it turns out that the other type rstctrl bits also need reset on init, we need to add an instance specific reset mask for the bits to avoid resetting unwanted bits.
Reported-by: Carl Philipp Klemm philipp@uvos.xyz Cc: Philipp Zabel p.zabel@pengutronix.de Cc: Santosh Shilimkar ssantosh@kernel.org Cc: Suman Anna s-anna@ti.com Cc: Tero Kristo t-kristo@ti.com Tested-by: Carl Philipp Klemm philipp@uvos.xyz Signed-off-by: Tony Lindgren tony@atomide.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/soc/ti/omap_prm.c | 11 +++++++++++ 1 file changed, 11 insertions(+)
diff --git a/drivers/soc/ti/omap_prm.c b/drivers/soc/ti/omap_prm.c index 4d41dc3cdce1f..c8b14b3a171f7 100644 --- a/drivers/soc/ti/omap_prm.c +++ b/drivers/soc/ti/omap_prm.c @@ -552,6 +552,7 @@ static int omap_prm_reset_init(struct platform_device *pdev, const struct omap_rst_map *map; struct ti_prm_platform_data *pdata = dev_get_platdata(&pdev->dev); char buf[32]; + u32 v;
/* * Check if we have controllable resets. If either rstctrl is non-zero @@ -599,6 +600,16 @@ static int omap_prm_reset_init(struct platform_device *pdev, map++; }
+ /* Quirk handling to assert rst_map_012 bits on reset and avoid errors */ + if (prm->data->rstmap == rst_map_012) { + v = readl_relaxed(reset->prm->base + reset->prm->data->rstctrl); + if ((v & reset->mask) != reset->mask) { + dev_dbg(&pdev->dev, "Asserting all resets: %08x\n", v); + writel_relaxed(reset->mask, reset->prm->base + + reset->prm->data->rstctrl); + } + } + return devm_reset_controller_register(&pdev->dev, &reset->rcdev); }