Re: Sierra Wireless EM9191 integration issues in mhi+wwan

From: Aleksander Morgado <aleksander@aleksander.es>
To: Thomas Perrot <thomas.perrot@bootlin.com>
Cc: Loic Poulain <loic.poulain@linaro.org>,
	Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>,
	Hemant Kumar <hemantk@codeaurora.org>,
	Thomas Petazzoni <thomas.petazzoni@bootlin.com>,
	linux-arm-msm <linux-arm-msm@vger.kernel.org>
Subject: Re: Sierra Wireless EM9191 integration issues in mhi+wwan
Date: Wed, 20 Oct 2021 10:43:09 +0200	[thread overview]
Message-ID: <CAAP7ucLCL37aYWMeqyj4eb-r6B-puZ+w9KeXMScpw3YhWgzXNA@mail.gmail.com> (raw)
In-Reply-To: <CAAP7ucJBed_5rCdyjWC9x8EkXn5+E7p4P46=ukAaC1vTFLdDAQ@mail.gmail.com>

Hey,

> This is the event ring configuration in the MBPL driver from Sierra,
> with NUM_MHI_EVT_RING_ELEMENTS=2048:
>
> static struct mhi_event_properties event_config[] = {
> /*    num                        intmod  msi chan    pri brs type
> hw_ev   c_m off  */
>     { NUM_MHI_EVT_RING_ELEMENTS,  1,      1,  0,      1,  2,  1,
> 0,      0,  0},
>     { NUM_MHI_EVT_RING_ELEMENTS,  1,      2,  100,    1,  3,  0,
> 1,      0,  0},
>     { NUM_MHI_EVT_RING_ELEMENTS,  1,      3,  101,    1,  3,  0,
> 1,      0,  0},
> //    { 240,  1,      3,  101,    1,  2,  0,      1,      0,  0},
> //    { 240,  1,      4,  0,      1,  2,  1,      0,      0,  0},
> };
>

Looking in detail at the table above, I can see at least 2 differences
between the Sierra MBPL driver and the upstream one:
 * In the upstream driver, MHI_EVENT_CONFIG_CTRL() sets
irq_moderation_ms to 0, while in the Sierra MBPL driver the table
above (intmod column) we can see it's set to 1 in channel 0.
 * In the upstream driver, MHI_EVENT_CONFIG_HW_DATA() sets mode to
MHI_DB_BRST_DISABLE(2), while in the Sierra MBPL driver the table
above (brs column) we can see it's set to MHI_DB_BRST_ENABLE (3) in
channels 100 and 101.

But changing those in my setup to be in line with the MBPL driver
didn't make any difference :/

-- 
Aleksander
https://aleksander.es